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MPS85 3 - Electro Systems Associates

1. Key Pressed Display Comments Address Field Data Field RESET UPS 85 System Reset GO XXXX XX GO command current PC and the byte at this PC are displayed 8 0008 New starting address 8 0088 0 0880 0 8800 EXEC UPS 85 Program is executed from 8800H Control returned to the monitor Example 2 Fill the registers A and C with OOH Execute the above program from 8800H Later examine the contents of reg A amp C Both the registers must contain 42H Key Pressed Display Comments Address Field Data Field RESET UPS 85 System Reset EXAM REG Examine register command A A XX Content of reg A 0 A 00 Reg A altered NEXT B XX Content of reg B NEXT C XX Content of reg C 0 C 00 Reg C altered EXEC Command terminated GO XXXX XX GOcommand Current PC and the byte at this PC are displayed 8 0008 New value of the PC 8 0088 0 0880 0 8800 EXEC UPS 85 Control returns to monitor EXAM REG Examine Reg command OAD MPS 85 3 User s Manual 1 21 QUO A A 42 Contents of reg A NEXT B XX Contents of reg B NEXT C 42 Contents of reg C EXEC Control returns to monitor due to the break point 3 4 6 SINGLE STEP COMMAND FUNCTION This command is used to execute a program one instruction at a time With each instruction executed control is returned to the monitor Thus this command is an extremely useful debugging tool
2. Yes button to change the setting of communication parameters Then user will observe the following dialog box sr Settings Bit Settings Port Settings IENA Data Bits BaudRate Com Port COM Stop Bits Parity Bits 7 Select the Baud rate as per the dipswitch configuration on MPS 85 3 Trainer Select the appropriate COM Port configured in PC and Click on OK button Now user can observe the following window On gt goo MPS 85 3 User s Manual 1 63 CONNECTED ARI NUM CAPs T COM2 9600 T0000 Trainer Detected COMMUNICATION SIGN ON MESSAGE STATUS 8 In some cases if the communication is not established user will get the error message dialog box as shown below In this case please check whether the MPS 85 3 Trainer is powered on Check whether Serial cable is connected properly between PC amp MPS 85 3 Trainer and check the parameters by clicking the Settings Serial Communication Message P Serial Communication Time Out 3 XXXXXXXXXXXXXXXXXXXXXXXXAXX SXAXXAXXXXXXXXXXXXXXX X XXXXXXXXX XXXXXX XXXXXX XXAXXXXXXXXXXX XXXX XX xX X LXXXXXX XXXXXX XXXXXXX XXXXXXN 4XXXXI XXXXXXXI XXXXXXX XXXXXX XXXX X SXXXXXX id XXXXXXX Bitte SXXX X XXXXXX 4 B a OAD MPS 85 3 User s Manual 1 64 JZ 9 Ifthe communication is established properly user can see the GUI of the application also can communicate with the trainer serially User can view the Regi
3. FORMAT SINGLE STEP lt Start address gt NEXT lt Start address gt NEXT EXEC OPERATION 1 To use this command press the SINGLE STEP key when prompted for command Now the contents of the user program counter are displayed in the address field and the byte at this location is displayed in the data field A dot also appears at the right edge of the address field indicating that the user can modify the value of the program counter if desired by entering the new address To execute the instruction at the current value of the program counter press the NEXT key When this key is pressed the instruction at the displayed address is executed the new value of user PC is displayed in the address field and its associated instruction byte is displayed in the data field The contents of the PC are again opened for optional modification by the user To terminate command press the EXEC key Note that after terminating the SINGLE STEP Command if you again press the SINGLE STEP key control returns exactly to the point where you pressed the EXEC key EXAMPLES Example 1 Assume the program given in Example 1 of GO Command illustration is entered in the memory Now this program can be single stepped as follows UAD QUO MPS 85 3 User s Manual 1 22 Key Pressed Display Comments Address Field Data Field RESET UPS 85 System Reset SINGLE STEP XXXX XX Current value of PC and the byte at this P
4. It does not consider whether the block being moved consists of program code or data Thus no relocation of program code occurs and the block is simply moved NOTE 2 The system determines if the destination block overlaps the source block It moves the data from either the starting address or from the ending address as required when overlap exists 3 4 8 INSERT COMMAND FUNCTION This command is used to insert one or more instructions into the user program FORMAT INSERT lt Low Limit gt NEXT lt High Limit gt NEXT lt Low Insert Address gt NEXT lt No of bytes gt NEXT lt data gt NEXT lt Data gt NEXT EXEC Oda 3 gt Z gop MPS 85 3 User s Manual 1 25 OPERATION This command together with the next command to be described viz DELETE provide the user mini editing facilities INSERT command allows the user to insert the desired number of bytes into a program at a specified address The address references in the program which change because of this insertion are automatically corrected by the monitor To do such corrections and to relocate the program the monitor must know Ad E b c d e Low Limit The starting address of the user program High Limit Present ending address of the user program Low Insert Address The address from where the bytes are to be inserted No of bytes The number of bytes to be inserted in hexadecimal notation and The actual bytes to be inserted To
5. This command allows the user to delete one or more instructions from a program The address references to be changed because of this deletion process are changed automatically by the monitor The interpretation of the parameters appearing in the format of the command is same as in the INSERT command described in the previous section 1 To use this command press the DELETE key when prompted for command entry Now the LOW LIMIT is displayed in the address field The LOW LIMIT can be optionally changed by the user Then the user must press the NEXT key Now the monitor displays the HIGH LIMIT After modifying this if desired press the NEXT key Now the display is cleared and a dot appears at the right edge of address field indicating that an address entry is required Enter LOW DELETE ADDRESS i e the address starting from which instructions are to be removed and press the NEXT key Again the display is cleared and a dot is displayed at the right edge of the address field Enter the HIGH DELETE ADDRESS i e the address of the last byte to be removed from the user program and press the EXEC key Monitor deletes all the bytes from LOW DELETE ADDRESS to HIGH DELETE ADDRESS It then makes appropriate changes to all address references in the program form LOW LIMIT to HIGH LIMIT ERROR CONDITION Specifying a LOW DELETE ADDRESS which is greater than HIGH LIMIT or HIGH DELETE ADDRESS E
6. otherwise the results are unpredictable 4 3 STRUCTURE OF MONITOR COMMANDS Whenever the monitor is ready to accept a command from the user it outputs a period C as the command prompt character at the beginning of a new line The commands entered by the user consists of a single character command mnemonic followed by a list of command parameters This list may consist of upto four parameters depending on the particular command being used When more than one parameter is required a single C is used between the parameters as a seperator Oda 3 gt 3 gop MPS 85 3 User s Manual 1 33 A command is terminated either by a Carriage Return or by a comma depending on the command itself Commands are executed one at a time and only one command is allowed within one command line PARAMETER ENTRY All numeric parameters are to be entered as hexadecimal numbers The valid range for one byte parameters is 00 to FF and if more than 2 digits are entered only the last two digits are valid leading zeros may be omitted Thus all one byte values are interpreted modulo 256 decimal The valid range for 2 byte parameters is 0000 to FFFF and longer values are evaluated modulo 64K i e only the last four digits are valid All the commands except the X examine modify register command require only hexadecimal values as parameters The register name abbreviation entries required by the X command are described later while describing the X comman
7. press the NEXT key OAD MPS 85 3 User s Manual QUO 3 Now a decimal point appears at the right edge of the data field indicating that the data byte to be output can now be entered using the hexadecimal keyboard enter the data byte to be output 4 After entering the data press the EXEC key to output the byte to the port and to terminate the command or press the NEXT key if additional data is to be output to the addressed port NOTE As mentioned in the previous section the I O ports provided on MPS85 3 their addresses and usage are explained in detail in chapter 5 Example Output a string of ASCII characters ESA to the data port of the USART 8251 to be transmitted to a CRT terminal through the on board RS 232 C interface Key Pressed Display Comments Address Field Data Field RESET UPS 85 System Reset OUT BYTE f Output Byte command 2 20 0020 Port address NEXT 2020 4 2020 04 5 2020 45 Send E NEXT 2020 5 2020 05 3 2020 53 Send S NEXT 2020 4 2020 04 1 2020 41 Send A EXEC Command termination prompt 3 4 5 GO COMMAND FUNCTION The GO command is used to transfer control of the system from the monitor to user s program FORMAT GO address EXEC Oda 3 gt gop MPS 85 3 User s Manual 1 19 OPERATION 1 To use this command press the GO key when prompted for command entry When this key is pressed the
8. 5 6 PROGRAMMABLE INTERVAL TIMER MPS 85 3 has an on board programmable interval timer 8253 5 at socket position U7 Its I O addresses can be found in Table 5 2 in section 5 4 8253 has one command status port and three data ports called Timer0 Timerl and Timer2 to provide three programmable timers Of these Timer 0 is utilized to drive the TRAP input of the CPU for implementing the Single Step facility SOD output from the CPU controls the gate input of this Timer 0 Timer 1 is utilized to generate Transmit and Receive clocks of 8251A Programmable Communication Interface However these signals as well as the signals related to Timer 2 are available on system connector J4 Thus if user does not require serial interface he she can make use of Timer 1 in addition to Timer 2 which is always available to user if required Connector details are provided in the last section of this chapter 5 7SERIAL INTERFACE An 8251A Programmable Communication Interface at position U9 is used for implementing RS 232C compatible serial interface This device is programmed for asynchronous operation 2 stop bits no parity data length of 8 bits and baud scale factor of 16X As already noted Timer 1 of 8253 is used to generate the required Transmit and Receive clocks of 8251A based on the setting of the DIP switch Refer section 2 1 2 on Baud selection The I O address of 8251A can be found in Table 5 2 in section 5 4 8251A is operated in a polled mode
9. 8000 FFFF 2732 at U2 4000 4FFF 5000 5FFF 6000 6FFF 7000 7FFF 2764 at U2 4000 S5FFF 6000 7FFF 27128 at U2 4000 7FFF When 2732 is installed at U2 the device responds to four address ranges due to address foldback Similarly when 2764 is installed at U2 the device responds to two address ranges 4000H to 5FFFH and 6000H to 7FFFH The three chip select signals are derived from BIO M BAI5 and BA14 The logic is implemented by 74 LS 139 at U13 74 LS 00 at U21 and 74 HC 32 at U20 Battery Option The RAM provided at U3 is backed up by an 3 6V Ni cd Battery by default 5 4 I O ADDRESSING I O decoding is implemented using a 74 LS 138 at U12 BIO M BA7 BA6 BAS and BA4 are only used to derive the chip select signals Thus foldback exists over the unused address lines The I O devices their addresses and their usage is summarized below OAD gt gon MPS 85 3 User s Manual 1 44 TABLE 5 2 TO ADDRESS MAP T O Device Address Usage 8255 1 at U22 Programmable Peripheral Interface PortA 00H Available to user PortB 01H PortC 02H The signals are available Control Port 03H on connector J1 8255 2 at U11 Programmable Peripheral Interface Port A 40H Port B 41H The signals are available to user at connector J2 Port C 42H Control Port 43H 8253 at U7 Programmable Interval Timer Timer 0 10H Timer 0 is required for Single Step facil
10. Kit for Sign on message 4 Check the Dipswitch Settings OAD gt z ceo MPS 85 3 User s Manual 1 73 CHAPTER S PROGRAMMING EXAMPLES 8 1 INTRODUCTION In this chapter we will describe some programming examples which can be run on the MPS 85 3 System The first set of examples are designed to illustrate the use of various command keys and the second set of examples are designed to illustrate the use of monitor routines The user encountering a microprocessor trainer for the first time is strongly urged to go through this chapter in detail load and execute the programs as indicated The experienced user can skip this section and directly refer to section 8 3 to become familiar with the use of monitor routines 8 2 PROGRAMMING EXAMPLES Example 1 The following program is a very short and simple one This program loads the registers B and C with specific values and stores a specific value ina RAM location Assume the program is to be loaded from 8800 H The program and the hand assembly is shown below LOCATION CONTENTS MNEMONIC COMMENTS 8800 06 22 MVI B 22H Initialize Reg B 8802 OE 82 MVI C 82H Initialize Reg C 8804 78 MOV A B 8805 32 40 88 STA 8840H Load the RAM location 8808 EF RST 5 Return control to the monitor Thus the sequence of 9 bytes to be stored from location 8800H through 8808H is 06 22 OE 82 78 32 40 88 EF Enter these using EXAM MEM command After entering
11. OAD MPS 85 3 User s Manual 1 76 QUO 8808 B7 ORA A multiplier 8809 CA 13 88 JZ OVER Yes Jump to OVER 880C 06 00 MVI B 00H clear B This is done so that DAD B we can use DAD Ins 880E 09 ADD DCR E ADD multiplicant 880F 1D JNZ ADD Decrement multiplier 8810 C2 OE 88 If multiplier is zero MOV A L Jump to ADD 8813 7D OVER STA 9000 H Save the L content to ACC 8814 32 00 90 MOV A H Store the ACC content in 9000 8817 7C STA 9001H Save the H content to Acc 8818 32 01 90 RST 3 Store the Acc content in 900 881B DF Return to monitor Now using the EXAM MEM command enter the above program After entering the last byte in to location 8810H you press the EXEC key Note that EXEC key is only a delimiter and it is not a command to start the execution of user program When you press the EXEC key after entering the last byte the EXAM MEM command is terminated and monitor returns to the command entry mode i e the display is cleared and a dash appears in the left most digit position of the display Now we have to set up the parameters for this program The parameters are the multiplicand and the multiplier Suppose we select their values as 1AH and 1AH They must be entered into the registers E and C Use EXAM REG command to enter these values Now we are ready to execute the program Note that if this program is part of a bigger program which usually will be the case then the last instruction would have been
12. REG Examine Register Command 8 H H XX Contents of register 8 H 08 New data NEXT L XX H register updated Next register s contents displayed EXEC Command termination prompt 3 4 3 INPUT BYTE COMMAND FUNCTION The INPUT BYTE command is used to input accept a byte of data from an input port FORMAT IN BYTE lt port address gt NEXT NEXT EXEC OPERATION 1 To use this command press the INBYTE key when prompted for command When this key is pressed the display is cleared and a decimal point appears at the right edge of the address field indicating that an address entry is required Enter the address of the port to be read Note that the port address can be in the range 0 255 decimal only Thus only 2 hex digits are required to specify the port address If longer value is entered the last four digits entered are displayed until the NEXT key is pressed Then only the last two digits are accepted as the port address In any case this port address is duplicated in the most significant two digits of the address field of the display After entering the port address press the NEXT key The addressed port is read and the data is displayed in the data field of the display Pressing the NEXT key again updates the data field display with the current data byte at the addressed input port Pressing the EXEC key terminates the command and the command entry prompt appears NOTE The I O ports provided on MPS
13. UPLOAD OPERATION This feature allows uploading the data from the memory of MPS 85 3 to the computer and saves the data in the specified disk file in INTEL 8 Bit HEX format 1 To perform upload operation click on upload button or go to file menu and choose upload option in the WIN853 dialog box Now user can observe the following dialog box Win853 Windows Driver for MPS 85 3 Trainer esx Files View Run Window Help CONNECTED Hl NUM CAPS COM2 9600 0000 stat aces a a a aD OAD MPS 85 3 User s Manual 1 69 JZ 2 Click on Browse tab and give the file name to be saved then user can find following dialog box Here user can select the path where the upload file should be saved n853 Windows Driver for MPS 85 3 Trainer Files View Run Window Help Upload Save HEX File File Name Path Hex Browse swns o ea Start Address 0000 ore Py oe End Address 0000 PRINTER B sax My Recent asx Senes3 Documents is pemocHip sx Ei DISPes Eres FIRE xtes Desktop kBINT MB xtes z MOHAN E ixtass Mon Mont PRINTER a sa gt SANDEEP My Computer File name resTPac z Save as type x CONNECTED HI NUM CAPS COM2 9600 Od 3 gt k ceo MPS 85 3 User s Manual 1 70 3 After saving the file enter the starting and ending addresses of the file which is to be uploaded and click on OK and the upl
14. a RET instruction But here we write RST 3 instruction so that control is returned to the monitor Then we can examine the results To start the execution of the program use GO key and provide the starting address 8800H Oda 3 gt 2 gop MPS 85 3 User s Manual 1 77 Now the display is cleared and E appears in the left most digit of display This always indicates that a user program is running But now what is happening The E has remained there We know that when control returns to the monitor via RST 5 instruction the monitor will display the command prompt and sign on message This present program is extremely short one and should not take more than a few milliseconds Thus E should be displayed only for a few milliseconds and then a dash should appear In fact we should not be able to notice E at all because it appears for such a short period Thus it is clear that the program is caught in infinite loop and control is never returning to monitor Now is the time for some debugging The first thing to do of course is to recover from the erroneous program i e allow the monitor to gain control The only way to do it now would be to press the RESET key Note that this type of situation is almost the only situation warranting the use of RESET key once you initialise the system Now go through the code carefully to see if there are any coding mistakes Assume we find one The next approach can be the single step command So rein
15. address to End address NOTE All three byte instructions are of memory reference type but for the following 4 instructions LXI B Value LXI D Value LXI H Value LXI SP Value Steps involved in using the RELCT routine In summary the steps involved in using the RELCT routine are as follows Step 1 Use the Block Move command to move the program code from the original area to the desired area Step 2 Set up the parameters required for the RELCT routine as explained above Step 3 Find 4 bytes of free RAM area and enter the following program CALL RELCT Call the monitor routine to relocate the code RST 5 Return to monitor Step 4 Execute the above program using the GO command Step 5 If required alter addresses which are not memory references if any Example 9 Consider the following simple subroutine which implements a delay Assume the program is assembled from 8840H LOCATION CONTENTS LABEL MNEMONIC 8840 01 FF 07 LXI B 07FFH 8843 0B DLY DCX B 8844 78 MOV A B 8845 B1 ORA C 8846 C2 43 88 JNZ DLY 8849 C9 RET LION MPS 85 3 User s Manual 1 85 QUO Let us assume that we want to relocate this program to the address 8850 H As already noted the first step is to move the code using the BLOCK MOVE command The required key sequence is BLKMOVE lt 8840 gt NEXT lt 8849 gt NEXT lt 8850 gt EXEC Note that the locations 8856 8857 and 8858 contain the values C2 43 88 Th
16. can be configured in a number of ways as determined by the settings of a DIP switch and other jumpers refer to the component layout diagram in Appendix C to locate the DIP switch and the jumpers This chapter describes all the configuration options and the installation procedures 2 1 1 OPERATIONAL MODE SELECTION MPS 85 3 can be operated either in the hexadecimal keypad mode or in the serial mode In the hexadecimal keypad mode the trainer is operated from the hexadecimal keyboard display unit In the serial mode the trainer is connected to a host PC through an RS 232C interface In either mode of operation the system provides a variety of commands for program development debugging The selection of the desired mode of operation is done as follows Switch 4 of the DIP switch Operational mode OFF Hexadecimal Keyboard mode ON Serial mode Default factory setting Chapter 3 describes the commands available in keyboard mode and chapter 4 describes the commands available in serial mode 2 1 2 BAUD RATE SELECTION In the serial mode of operation MPS 85 3 configures the on board 8251A USART as follows OAD gt gon MPS 85 3 User s Manual 1 4 asynchronous mode 8 Bit character length 2 stop Bits no parity Baud Rate factor of 16X o o Timer 1 of the on board 8253A provides the transmit and receive baud clocks for the USART Refer chapter 5 for a detailed discussion of the Hardware This tim
17. current contents of the User Program Counter are displayed in the address field and the contents of the location addressed by the PC are displayed in the data field A dot also appears at the right edge of the address field indicating that the user can update the value of User Program Counter if required To begin Program execution press EXEC key Now the address and data fields are cleared and E is displayed at the left edge of the address field and control is then transferred to the user program at the current value of the user program counter To return control to the monitor you can write the RST 5 instruction opcode EFH at the end of your program When this instruction is executed monitor regains control of the system and full information about the user program is saved Another way to exit from a running program and return control to the monitor is to press the RESET key However in this case all register information about user program is lost Note that in any case the contents of the user portion of the RAM area are not disturbed by the Monitor Example 1 Suppose the following program is entered in the memory by EXAM MEM command Location Object Code Mnemonic 8800 3E MVI A 42 8801 42 8802 4F MOV C A 8803 EF RST 5 To run this program press the keys according to the following sequence OAD MPS 85 3 User s Manual QUO 1 20
18. label is being defined by a SET directive after it has been defined earlier by means other than through the SET directive Oda 3 gt gop MPS 85 3 User s Manual 1 101
19. the start of pass 2 when the number of labels is greater than what can be accommodated in the label table The pass 1 is aborted as soon as this occurs but Pass 2 goes on with some of the internal references going unlabelled This message stays on the screen for 75 seconds and Pass 2 starts thereafter Invalid code H This is displayed if a invalid opcode is encountered with the message listing the illegal opcode and its location This message is first displayed in Pass 1 and aborts it and it is again displayed in Pass 2 with the Disassembly aborted thereafter 9 3 ASSEMBLER If the user types A from the main menu the assembler signs on as MPS 85 Assembler Vx y 9 3 1 Main Features This is a two pass assembler which supports a powerful set of assembler directives that enhances the use of the MPS 85 3 microprocessor trainer towards a complete and thorough understanding of the 8085 microprocessor and its programming concepts The assembler also supports a sufficient range of expressions The assembler prompts for the start and the end of the source text buffer and also that for the symbol table as Text Buffer 9000 A7FF Starting Address Ending Address Label Table A800 AFFF Starting Address Ending Address Oda 3 gt r gop MPS 85 3 User s Manual 1 94 The values shown enclosed within the square brackets are the default values and are chosen when no values are entered and a lt CR gt is ty
20. user through the rest of the installation procedure Once the Software is installed successfully WIN853 offers a complete online help for working with the commands Under WIN853 the trainer can communicate at a baud rate of up to 38400 7 3 1 INSTALLATION PROCEDURE 1 Run Setup exe from the Drivers Software CD Now user can observe the following dialog box which will copy the required files from Source CD to the Host PC Install Od 3 gt k ceo MPS 85 3 User s Manual 1 58 3 Windows Driver for MPS 85 3 Trainer Setup X Welcome to the Windows Driver for MPS 65 3 Trainer installation program 4 gest Setup cannot install system files or update shared files if they are in use Before proceeding we recommend that you close any applications you may be running Click this button to install Windows Driver for MPS 85 3 Trainer software to the specified destination directory C Program Files WINGS3 Change Directory 3 The default Installation directory will be C ProgramFiles WIN853 User can change the installation directory by clicking Change Directory 4 Click the highlighted Icon shown above to continue the Installation Procedure then observe the following Dialog Box Oda 3 gt z gop MPS 85 3 User s Manual 1 59 JI Windows Driver for MPS 85 3 Trainer a Choose Progra Setup will add items to the group shown in the Program Group box You can enter a new group name or se
21. 10H 18 BLKMOVE 11H OAD MPS 85 3 User s Manual 1 46 QUO 19 F2 12H 20 INSERT 13H 21 IN BYTE 14H 22 DELETE 15H 23 OUT BYTE 16H 24 PREV 17H 25 SINGLE STEP 18H 26 GO 19H 27 EXAM MEM 1AH 28 EXAMREG 1BH 29 NEXT 1CH 30 EXEC 1DH NOTE RESET and KBINT keys are not connected to keyboard controller Display Drive The segment drive outputs of 8279 AO through A3 and BO through B3 form a single 8 bit parallel output driving the display element segments The correspondence between the data bus segment outputs of 8279 and the display element segments is shown below TABLE 5 4 Display Segment Control To D6 D Al AC d dp Segment d c a dp g e Example To display E the data format requires that segment a f g e and d should be ON and other segments should be OFF So the data should be 1001 0111 97H Display codes for other patterns can be worked out similarly Oda 3 gt gop MPS 85 3 User s Manual 1 47 Display Position To display characters in the address field 8279 must be instructed to start from display position 0 by sending 90H to the command port of 8279 and to display characters in the data field 8279 must be instructed to start from display position 4 by sending 94H to the command port of 8279 For further details regarding display codes and display procedures user can refer the Monitor Program Listing supplied along with MPS 85 3
22. 85 3 their addresses and usage are described in detail in chapter 5 on Hardware Oda 3 gt gop MPS 85 3 User s Manual 1 17 Example Input the byte from the port 50H i e baud switch status Key Pressed Display Comments Address Field Data Field RESET UPS 85 System Reset IN BYTE Input Byte command 5 0005 Port Address 0 0050 Input data byte NEXT 5050 XX NEXT 5050 XX Current data byte NEXT 5050 XX Current data byte EXEC Command termination prompt 3 4 4 OUTPUT BYTE COMMAND FUNCTION The OUTPUT BYTE command is used to output a byte of data to an output port FORMAT OUTPUT lt port address gt NEXT lt data gt NEXT lt data gt EXEC OPERATION 1 To use this command press the OUTBYTE key when prompted for command When this key is pressed the display is cleared and a decimal point appears at the right edge of the address field indicating that an address entry is required Enter the desired port address Note that the port address can be in the range 0 255 decimal only Thus only 2 hex digits are required to specify the port address If longer value is entered the last four digits entered are displayed until the NEXT key is pressed Then only the last two digits are accepted as the port address In any case this port address is duplicated in the most significant two digits of the address field of the display After entering the desired port address
23. 8846 C2 43 88 JNZ DLY 8849 C9 RET If you move the above block of code to another location say 8850H then it will not work correctly The instruction at 8846H will be JNZ 8843 while it should be JNZ 8853 as the value of the label DLY is now 8853H All such address references must be adjusted appropriately for Oda 3 gt gop MPS 85 3 User s Manual 1 83 the moved program to work properly Such a process of adjustment is called Relocation Of course this is a simplistic view but adequate for the present discussion Such a relocation feature is an extremely convenient tool for debugging As an example suppose you want to debug a program located in a PROM As the program is in a PROM you can t conveniently introduce any code patches to try out alternatives If you can relocate such a program into RAM area it will be a simple matter to introduce the necessary code patches This is just one example There are many other situations where a Relocation facility can be put to good use MPS 85 3 provides the user with a convenient tool for such a relocation This is done through a monitor routine RELCT whose calling address is 0533H Now we describe the use and limitations of this routine Using the Relocation routine RELCT To use this routine the following parameters must be set to appropriate values Memory Location Parameter Description SFE9 8FEA Relocation offset OFSTAD Relocation offset New starting Addres
24. C 8 0008 8 0088 0 0880 New value of PC 0 8800 NEXT 8802 4F Instruction at 8800 is executed Next instruction to be executed is displayed NEXT 8803 EF Next instruction EXEC Command termination 3 4 7 BLOCK MOVE COMMAND This command is used to move a block of data from one area of the memory to another area FORMAT BLK MOVE lt Start address gt NEXT lt end address gt NEXT lt destination address gt EXEC OPERATION 1 To use this command press the BLK MOVE key when prompted for command entry When this key is pressed display field is cleared and decimal point appears at the right edge of the address field 2 Now enter the starting address of the block of data to be moved Press the NEXT key Now the display field is again cleared and again a decimal point appears at the right edge of the address field Now enter the ending address of the block of data to be moved Press the NEXT key Monitor clears the display field and a decimal point appears at the right edge of the address field Now enter the starting address of the area into which the block of data is to be moved This address is called the destination address Press the EXEC key to start the command execution OAD MPS 85 3 User s Manual QUO 1 23 3 Monitor now moves the block of data from start address to end address to the area beginning at the destination address After moving the data monitor displays the command prompt sign ER
25. CHAPTER 1 INTRODUCTION MPS 85 3 is an extremely powerful microprocessor trainer based on the popular 8085 CPU It can be used as a flexible instructional aid in academic institutions Following are the main features of MPS 85 3 MPS 85 3 can be operated either from on board keyboard or from a host PC through its RS 232C interface e Keyboard and serial monitor programs support the entry of user programs editing and relocation debug facilities like breakpoints and single stepping direct port input output and full speed execution of user programs 32K Bytes of CMOS static RAM is provided with battery backup Total on board memory can be upto 64K Bytes Allows multi processor system design by supporting the HOLD and HLDA signals OAD gt gon MPS 85 3 User s Manual 1 1 Options Available a Interface Modules for training purpose Calculator Keyboard Elevator Display ADC with DAC Dual Slope ADC Dual DAC Logic Controller Crystal Clock Divider Traffic Lights RTC Tone Generator Stepper Motor 8 bit 16 Channel ADC etc b 26 Core Ribbon Cable Connector Set SPECIFICATIONS CPU Memory Firmware 8085 Operated at 3 072 MHz Three 28 pin JEDEC sockets offer 64K Bytes of memory as follows 16 K Bytes of firmware in one 27128 4K 8K 16K expansion through 2732 2764 6264 27 128 32KB of static RAM using one 62256 with battery backup Serial and Keyboard Monitors Centronics Printer Interface Dr
26. D Where n is the number of lines deleted Replace Syntax R In This command lets the user replace the contents of an existing line specified by the parameter In with the new contents At the execution of the command the following format is displayed In the present content of the line In Now the new content can be typed and executed with a lt CR gt NOTE The old content can be retained at any stage if lt CR gt is executed without typing any character Exit Syntax X The Editor first display the current file name maintained in the buffer FILE NAME XXXX Oda 3 gt K gop MPS 85 3 User s Manual 1 91 This can be optionally changed by typing in a new file name Otherwise only lt CR gt will retain the old file name Then it displays the current parameters of the previous buffer area Starting Address SSSS Ending Address EEEE This will be followed by the following prompt SAVE Y N Responding with Y will save the buffer content in the cassette tape Audio tape interface must be connected externally to the trainer and Recording keys to be depressed before selecting this option Typing N will take you out of the Editor to the main menu 9 1 2 ERROR DESCRIPTION Bad Command This occurs when the command is not recognised This may also occur when user tries to operate on lines that do not exist or give a list command when the buffer is empty Tape Error This occurs when the fil
27. H the start of keyboard monitor Oda 3 gt gop MPS 85 3 User s Manual 1 13 Key Pressed Display Comments Address Field Data Field RESET UPS 85 System Reset EXAM MEM Examine Memory command 0 0000 First memory location To be examined 0000H NEXT 0000 F3 Contents of this location NEXT 0001 3E Next location and its contents NEXT 0002 OF Next location and its contents PREV 0001 3E Previous location and its contents EXEC Command termination prompt RESET UPS 85 System Reset EXAM MEM Examine Memory command 8 0008 D 008D Memory location to be examined amp modified 0 08DO 0 8D00 NEXT 8D00 XX Contents of this location A 8D00 OA New data to be entered F 8D00 AF EXEC Command termination prompt To check that data was updated successfully press EXAM MEM key and enter memory address 8DOO0H and note that AF is displayed in the data field when NEXT key is pressed Example 3 Trying to modify ROM location Key Pressed Display Comments Address Field Data Field RESET UPS 85 System Reset EXAM MEM Examine Memory command A 000A Address of location to be examined NEXT 000A 10 Contents of this location F 000A OF A 000A FA New data to be entered NEXT Err Error message OAD MPS 85 3 User s Manual QUO You tried to modify the contents of a Read Only Memory location Hence t
28. However character input routine can be made interrupt driven by shorting JP6 A amp B and writing suitable RST 6 5 service routine Refer section 2 1 4 The TXD RXD CTS RTS signals are given to MAX232 U10 to make an RS 232C compatible The RS 232C compatible signals are available on 9 pin D type female connector J6 Refer the last section of this chapter for connector details NOTE If the handshake signals are not required user can short DTR DSR and RTS CTS Oda 3 gt gop MPS 85 3 User s Manual 1 48 5 8 PROGRAMMBLE PERIPHERAL INTERFACE DEVICES MPS 85 3 has two numbers of 8255As Programmable Peripheral Interface Devices Each 8255A consists of a command port and three 8 bit programmable input output ports called Port A Port B and Port C The port addresses of these devices can be found in Table 5 2 in section 5 4 The two 8255As at U11 and U22 are completely available to user The port signals are available on connectors J2 and J1 Refer the last section of this chapter for connector details 5 9 WAIT STATE LOGIC MPS 85 3 accesses on board memory and I O devices with zero wait states However the READY input to the CPU is available on system connector J3 and user can drive this signal low to introduce wait states if required NOTE READY is pulled up to VCC through a 4 7K ohm resistor on MPS 85 3 5 10 INTERRUPTS AND HOLD RST5 5 RST6 5 and RST7 5 inputs can be driven by either on board signals 8279INT RXRDY an
29. ION MPS 85 3 trainer kit is supplied with Windows and DOS driver packages which allow the user to establish communication between the MPS 85 3 trainer in serial mode and a Host PC through its asynchronous communication ports COM1 COM2 COM3 COM4 etc Both the packages fully support the MPS 85 3 Serial Monitor commands including file upload and download facilities HEX files generated by PC native and Cross tools can also be downloaded to the trainer using these packages Further data from MPS 85 3 memory can also be uploaded to the computer The compatible serial cable for RS 232C communication is also included in the package 7 2 INSTALLATION a Configure MPS 85 3 for serial mode of operation and set the serial port of MPS 85 3 for 9600 Baud rate and No parity Refer Chapter 2 b Connect the Host PC to MPS 85 3 over the serial COM port using the serial cable provided Refer to system s Technical Manual for details regarding the signal definitions on COM ports Refer appendix C of this manual for serial cable details 7 3 INSTALLATION OF WIN853 WIN853 is a Windows based Communication package for MPS 85 3 trainer that provides a powerful and convenient debugging and development environment to the user The user must install this software from the MPS 85 3 Drivers CD OAD gt j gon MPS 85 3 User s Manual 1 57 Insert the CD in the CDROM drive and run Setup exe from the WIN853 s folder The Setup program will guide the
30. MPS 85 3 User s Manual 1 50 QUO 11 20 PB2 24 10 PC7 12 21 PB3 25 26 5V 13 18 PBO 26 7 GND CONNECTOR J3 PIN NO SIGNAL PIN NO SIGNAL 1 BSO 2 BS1 3 RST 6 5 4 KBRST IN 5 INTR 6 RDY 7 MOD IO M 8 BHOLD 9 BAI5 10 BAI4 11 BA13 12 BA12 13 BAI 14 BA10 15 BA9 16 BA8 17 VCC 18 VCC 19 BA7 20 BA6 21 BAS 22 BA4 23 BA3 24 BA2 25 BAI 26 BAO CONNECTOR J4 PIN NO SIGNAL PIN NO SIGNAL 1 CLK1 2 GATE1 3 OUT2 4 GATE2 5 CLK2 6 OUTI 7 RST 5 5 8 GND 9 BIO M 10 BCLK OUT 11 ALE 12 BRST OUT 13 BWR 14 BHLDA 15 BRD 16 BINTA 17 GND 18 GND 19 BDI 20 BDO 21 BD3 22 BD2 23 BD5 24 BD4 25 BD7 26 BD6 OAD MPS 85 3 User s Manual QUO 151 CONNECTOR J6 PIN NO FUNCTION GND RXD TXD DTR GND DSR RTS CTS 2 20 YN Hy Be NC All the remaining pins are not connected in the above J6 connector Note If your terminal does not support handshaking signals loop RTS amp CTS and DSR amp DTR Also remember MPS 85 3 TXD should be connected to terminal RXD and so on Oda 3 gt 2 gop MPS 85 3 User s Manual 1 52 CHAPTER 6 MONITOR ROUTINES ACCESSIBLE TO USER MPS 85 3 monitor offers several user callable routines both in the keyboard and serial modes of operation de
31. N reset If you change the settings either press the RESET key or switch OFF and then switch ON the power supply If the problem persists please contact the manufacturer service center Oda 3 gt gop MPS 85 3 User s Manual 1 9 CHAPTER 3 KEYBOARD MONITOR 3 1 INTRODUCTION This chapter describes the commands supported by the keyboard monitor program In the keyboard mode the user enters the commands and data by pressing the appropriate keys on the keypad Responses are displayed by the system on the six digit LED display Whenever the monitor expects a command the display shows a dash at the left edge of the address field possibly along with an error message or with the sign on message upon reset Thus it should be noted that irrespective of the characters appearing in the rest of the display a dash at the left edge of the display always is a command prompt When the monitor expects a parameter a decimal point will be displayed at the right edge of the field into which the parameter is to be placed The parameter will be either an address to be entered in the address field or a byte of data to be entered in the data field The only exception explained later occurs in the use of the EXAM REG command The valid range for an address parameter is from 1 to 4 hexadecimal digits and the valid range for a data parameter is from 1 to 2 hexadecimal digits Longer numbers may be entered but such numbers are evaluated m
32. O 8806 OE 20 MVI C 20 ASCII code for space 8808 CD 2D 0C CALL SOUTPT Output it to USART OAD MPS 85 3 User s Manual QUO 1 82 880B OE 20 MVI C 20H ASCII code for space 880D CD 2D 0C CALL SOUTPT Output it to USART 8810 21 08 89 LXI H 8908H Start of the second message 8813 CD 5B OB CALL DISPM Displays the second word SYSTEMS 8816 DF RST 3 Return to monitor 8900 45 4C 45 43 54 52 4F 00 8908 53 59 53 54 45 4D 53 00 Enter the program in locations 8800H to 8811H and data from 8900 to 890F using S command And using G command execute the program Then ELECTRO SYSTEMS will be seen on the console NOTE This program as well as the earlier programs can be entered using the Text Editor and assembled using the resident Assembler Disassemble the code using the Disassembler before executing the programs to see the machine codes generated 8 4 RELOCATION OF PROGRAMS What is Relocation Suppose you have a program assembled from a given location If you move the program code to a different location generally it will not work properly This is because of the fact that all jump call and direct load instructions will be having address references pointing to the old locations As an example consider the following DELAY subroutine LOCATION OPCODE LABEL MNEMONIC 8840 01 FF 07 LXI B 07FFH 8843 OB DLY DCX B 8844 78 MOV A B 8845 Bl ORA C
33. ROR CONDITIONS 1 Specifiying a value for the end address of the source block which is less than the value of the start address of the source block Ze Trying to move the data into non existent or Read Only Memory EXAMPLES Example 1 Moving the block of program code listed in the example for the GO command Key Pressed Display Comments Address Field Data Field RESET UPS 85 System Reset BLK MOVE Block move command 8 0008 Start address of source block 8 0088 0 0880 0 8800 NEXT 8 0008 End address of source block 8 0088 0 0880 3 8803 NEXT 8 0008 Destination address 8 0088 2 0882 0 8820 EXEC Block move operation successful Command prompt LION MPS 85 3 User s Manual 1 24 QUO Now using the EXAM MEM key observe the contents of the locations 8820H 8821H and 8823H and verify that the code has indeed been moved into the destination block EXAMPLE 2 Trying to move into EPROM area Key Pressed Display Comments Address Field Data Field RESET UPS 85 System Reset BLK MOVE i Block move command 0 0000 Start address NEXT F OOOF End address NEXT 2 0002 Destination address 0 0020 EXEC Err Attempt to move data into ROM area resulted in error message Command prompt NOTE 1 Block move moves a block of data contents from one area to another area
34. S 85 3 trainer in serial mode operation at baud rate 9600 default by keeping the switch 4 of 8 way DIP switch ON Position e Connect one end of RS 232C cable to trainer and the other end to a host PC terminal for serial communication Execute the WIN853 software or any terminal emulation software e Switch ON Power supply to trainer then the sign on message MPS 85 SERIAL MONITOR Vx y will be displayed on the WIN853 Command window e Execute the program from 2000H using GO command then the following menu will be displayed on the WIN853 Command window e MPS 85 Editior Assembler System Vx y E Editor D Disassembler A Assembler X Exit E D A X X exits editor assembler and returns to the Serial Monitor The detailed explanation of each module is given under the corresponding sub heading Oda 3 gt gop MPS 85 3 User s Manual 1 88 9 1 EDITOR If E is typed the editor module is invoked 9 1 1 Main Features This is a text editor with full text editing facility that includes Insert Delete List Replace and Exit commands It also supports loading programs from an audio cassette tape and saving an edited text onto the tape The editor requires the length of the line to be a maximum of 72 characters and the lines are terminated by end of line marker ODH The end of file marker is a 1AH While loading from a tape if the EOL EDF marker combination is not present at the end of the fil
35. SET IN SELECTION The sources for the vectored interrupts RST5 5 RST6 5 RST7 5 and the TRAP can be selected to be either on board signals or off board signals However please note that the source for TRAP is configured to be the OUTO signal from the timer This selection is necessary for implementing the single step facility provided by both the keyboard monitor and serial monitor Further the reset input to the CPU can be selected to come from either the on board RESET key or from an off board source Their default settings are shown below Jumper setting Interpretation Connector amp pin no JP3 AB RST 7 5 source is external signal RST7 5 J3 7 JP7 BC RST 7 5 source is on board signal KBINT JP6 AB RST 6 5 source is external signal RST6 5 J3 3 BC RST 6 5 source is on board signal RXRDY JP5 BC RST 5 5 source is external signal RST5 5 J4 7 AB RST 5 5 source is on board signal 8279 INT J4 7 CD RST 6 5 source is external signal RST6 5 Default factory setting Connector amp pin no indicates to which pin of which connector external signal has to be connected Oda 3 gt x gop MPS 85 3 User s Manual 1 6 2 2 INSTALLATION OF MPS 85 3 To install MPS 85 3 the following accessories are required a Power Adapter 5V 3 0 Amp b For Serial mode of operation Host PC with RS 232C interface with the driver software for host PC Refer chapter 7 for deta
36. TION CONTENTS MNEMONIC COMMENTS 8FBF C3 20 88 JMP 8820 Jump to RST7 5 service routine Enter these bytes using EXAM MEM command Now at 8820H we must write the service routing LOCATION CONTENTS LABEL MNEMONIC COMMENTS 8820 F5 PUSH PSW save counter 8821 E6 03 ANI 03 Mask off the most significant 6 bits 8823 32 Fl 8F LOOP STA 8FFIH 8826 06 00 MVI _ B 00 No Dot 8828 CD 4C 04 CALL UPDDT Display the number 882B F1 POP PSW Restore counter 882C FB EI Enable interrupts 882D C9 RET Return to main program Notice the EI instruction before the RET instruction This is required as interrupts are disabled once an interrupt is recognized As we want to recognize the interrupts again we must enable them before returning to the main program Load the above service routine Execute the program at location 8800H Now whenever the KBINT key is pressed a value between 0 and 3 is displayed in the data field As this program is an infinite loop to recover you must press the RESET key Example 8 This example illustrates the use of a serial monitor routine to display a message on the console In the following program it displays ELECTRO SYSTEMS on the console LOCATION CONTENT MNEMONIC COMMENTS 8800 21 00 89 LXI H 8900H Start of the first message 8803 CD 5B 0B CALL DISPM Displays the first word ELECTR
37. XAMPLE This example illustrates the use of INSERT and DELETE commands Assume that the following program has already been entered in to memory using the EXAM MEM Command LOCATION VALUE INSTRUCTION 8830 C5 PUSH B 8831 0B DELAY DCXB 8832 78 MOV A B 8833 Bl ORA C 8834 C2 JNZ DELAY 8835 31 8836 88 8837 Cl POP B 8838 D1 POP D 8839 El POP H 883 A C9 RET HAD MPS 85 3 User s Manual 1 28 QUO Now suppose you discovered that you did not intialise BC register pair before starting the DELAY You can insert one instruction say LX1 B 3030H starting at the location 8831 by the following key sequence Key Pressed Display Comments Address Field Data Field RESET UPS 85 System Reset INSERT XXXX Current Low Limit 8 0008 The Low Limit of user program 8 0088 3 0883 0 8830 NEXT XXXX Current High Limit 8 0008 The High limit of the program 8 0088 3 0883 A 883 A NEXT f 8 0008 Low insert address 8 0088 3 0883 1 8831 NEXT f 3 0003 Insert one instruction of 3 bytes NEXT 8831 XX Start entering the instruction 1 8831 Ol NEXT 8832 XX 3 8832 03 0 8832 30 NEXT 8833 XX 3 8833 03 0 8833 30 EXEC Instruction inserted return to command Prompt OAD MPS 85 3 User s Manual QUO 1 29 To see that the instruction has indeed be
38. a Carriage Return is to be entered Further when describing the individual commands with example output from the system is underlined These symbols are used only to clarify the command formats and they are to be neither entered by the user nor output by the system TABLE 4 1 SUMMARY OF SERIAL MONITOR COMMANDS COMMAND FUNCTION FORMAT C Compare Memory Compare a block of memory with destination block C lt Start address gt lt end address gt lt destination address gt lt CR gt Aa D lt Start address gt lt end address gt lt CR gt Transfers the processor control from the Monitor to user program with optional breakpoints G lt Start address gt lt breakpoint address 1 gt lt breakpoint address 2 gt lt breakpoint address 3 gt lt CR gt M Move Memory Moves a block of memory contents M lt Start address gt lt end address gt lt destination address gt lt CR gt S Substitute Memory Displays Modifies memory locations S lt address gt lt new data gt lt CR gt X Examine Modify Registers Displays Modifies the processor registers X lt reg gt lt new data gt lt CR gt Oda 3 gt 3 gop MPS 85 3 User s Manual 1 35 4 4 1 S SUBSTITUTE MEMORY COMMAND FUNCTION The S Substitute Memory command is used to examine the contents of specified memory locations Further if the locations are in RAM their contents can be altered if desired FORMAT S lt address
39. ained as follows Insert Syntax I or I or I in T Command allows you to insert at the beginning of the file If the file is opened for the first time the following message is displayed NEW FILE 0001 Where 0001 is the first line number T command lets you insert at the end of the file T in command inserts just before the line specified by the line number parameter in NOTE a The line number gets increment by one every time a lt CR gt is executed b CTRL A aborts the current line and terminates Insert mode and reenter back to the Editor command List Syntax L or Lin or L Inl 1n2 L command display the content of the complete file L In command display the line specified the 1n parameter Oda 3 gt K gop MPS 85 3 User s Manual 1 90 L Inl 1n2 command displays all the lines starting from line 1n1 to line 1n2 The display scrolling can be halted at any point by CTRL S and restarted by any other key The listing can be aborted at any time by CTRL C Delete Syntax D 1n or D1n1 1n2 D 1n command deletes the line specified by the line number parameter In D1nl 1n2 command deletes all the lines starting from line 1n1 to line 1n2 NOTE a Ifthe 1n2 parameter is greater than the total number of lines then 1n2 takes the value of the last line number b At the end of deletion the following message is displayed N LINES DELETE
40. alues Parameters are set up as follows Reg DE Value 1 Reg HL Value 2 The difference between the two values is available in DE and carry is set as shown Carry 1 if value 1 lt Value 2 0 otherwise DE Value 1 Value 2 030EH GTHEX Gets hex digits and displays them This routine collects the hex digits entered from the keyboard and forms a 2 digit or 4 digit hex number Parameters Reg B 0 Display the received value in address field Display the received value in data field 03BAH RDKBD Reads keyboard This routine waits until a character is entered from the system keyboard and upon return it places the character in the A register The register A and F F s are affected 034FH HXDSP Expands hex digits for display This routine expands hex digits and stores them in the specified buffer OUTPUT routine can now be used to display this number parameters Reg DE Hex value to be expanded Registers A H L and flags are affected 0553H RELCT Refer Section 8 4 OAD MPS 85 3 User s Manual QUO 1 54 6 2 SERIAL MONITOR ROUTINES ACCESSIBLE TO USER Calling Address Mnemonic Functions 0C12H GETCH Gets one character from the USART Input parameters None Output C Character ASCII received from USART Regs A C and flags are affected 0C2DH SOUTPT Outputs one character to the USART Inputs C Character ASCID to be out
41. austed then the message Label Table Exhausted is displayed and the assembly is aborted with only the partially completed error listing displayed ID ERROR CODES a E Expression Error This error occurs when the expression cannot be evaluated due to reasons like e The digit doesn t confirm as the correct digit for the number system implied e Number system other than Binary Octal Decimal and Hexadecimal is implied Incorrect mathematical operator i e other than addition subtraction multiplication or division Undefined label Number of segments in the expression is more than two Missing mathematical operator Only one segment in the expression through a mathematical operator is present Oda 3 gt gop MPS 85 3 User s Manual a b S Syntax Error This is an error that occurs when the syntax of the source line is improper due to reasons like c Too long a label Illegal characters in the label field Illegal mnemonic Illegal pseudo opcode Missing label field for pseudo ops like SET and EQU Missing operand field for some mnemonics and pseudo ops Incomplete operand field The expression evaluates to a value greater than 1 Byte for immediate instruction allowing only 1 Byte data M Multiple Definition Error This is caused due to the following reasons The same label has been used to define something else earlier except by means of a SET directive The
42. by To Windows To remove a program or to modify its installed components select it from the list and click Add Remove TRACE 32 U Storage 2 0 Windows Driver for ESA 31 Trainer Windows Driver for MPS 85 3 Trainer WinDriver winzip Yahoo extras Yahoo Internet Mail Yahoo Toolbar 2 Select the Driver to Uninstall and click Add Remove Then the following dialog box will appear which will ask for confirmation Application Removal 3 Click Yes to uninstall otherwise No to come out from the uninstallation procedure 4 Delete the installation Directory manually C Program Files WIN853 Oda 3 gt gop MPS 85 3 User s Manual 1 62 7 5 CONFIGURING THE INSTALLATION 1 Switch on the PC 2 Connect the supplied RS 232C serial cable between the connector J6 9 pin D type female of the MPS 85 3 Trainer and COM port of the Host PC 9 pin D type male 3 Power up the MPS 85 3 trainer using 5V DC power supply 4 Set the baudrate for 9600 bps using the Dipswitches on the MPS 85 3 Trainer Refer chapter 2 5 Open the WIN853 application on the Host PC from the start button of the Microsoft windows Now user can observe the following Dialog Box MPS 85 3 win853 ini Not Found A Serial parameters are set to 9600 COM1 8 1 None Do you want to change No 6 If the PC COM port is already set for COM1 and the baud rate set for 9600 bps then click on No button otherwise Click on
43. continues till the contents of end address are compared with those of the corresponding location in the 2nd block Any differences detected are displayed EXAMPLES 1 Compare the contents of memory locations 8000H to 80FFH with those of a memory block beginning at 8800H C 8000 80FF 8800 lt CR gt This response showed that there is no mismatch 2 Compare the contents of memory locations 8100H to 81FFH with those of a memory block beginning at 8300H C 8100 81FF 8300 lt CR gt 81C0 00 83CO FF 81D8 48 83D8 54 This response showed that there is mismatch at two locations Oda 3 gt gop MPS 85 3 User s Manual 1 39 4 4 5 X EXAMINE MODIFY REGISTERS COMMAND FUNCTION This command is used to examine and optionally modify the contents of the registers FORMAT X lt reg gt lt new data gt lt CR gt OPERATION 1 To examine the contents of all the registers enter X followed by carriage return when prompted for command entry The monitor will now display the contents of all the registers 2 If you wish to examine modify the contents of a particular register then enter X when prompted for command followed by the register name abbreviation The register name abbreviations are shown in Table 4 2 Now the monitor will output an equal sign the current contents of the specified register and data prompt character The contents of this register can be changed now by entering the new data val
44. d KBINT or by off board signals RST5 5 RST6 5 and RST7 5 via connectors J3 and J4 Refer section 2 1 4 The system monitor does not make use of these vectored interrupts Thus while in the monitor these interrupts are masked and disabled When these vectored interrupts are recognized the CPU saves the PC and starts execution from specific memory locations To allow the use of these interrupts by the user the monitor has JMP instructions at these locations The target of these JMP instructions is RAM area For example when RST 7 5 is recognized CPU pushes the current PC onto the stack and executes the instruction at 3CH The instruction at 3CH is JMP 8FBFH Thus now the control comes to 8FBFH Three bytes are available to user from 8FBFH Thus user should enter another JMP instruction at 8FBFH using for example Examine Memory command and this JMP must be to the service routine written by the user The RAM locations corresponding to different RST instructions and vectored interrupts are shown below TABLE 5 5 RAM addresses for interrupts Interrupt Corresponding RAM location RST 5 5 8FB3H RST 6 8FB6H RST 6 5 8FB9H RST 7 8FBCH RST 7 5 8FBFH OAD MPS 85 3 User s Manual 1 49 QUO Chapter 8 on Programming Examples includes an example illustrating the use of RST 7 5 interrupt In a similar way user can make use of the other interrupts TRAP input is connected to Timer 0 output for single step implementa
45. d in detail RESPONSE TO ERRORS Whenever an error is detected by the monitor either in the command entry orin the command execution the command is aborted the symbol C is output on the command line a carriage return and a linefeed are issued and the command prompt character is output at the beginning of a new line The possible error conditions are described while illustrating the individual commands Command execution occurs only after a valid delimiter a comma or a carriage return depending on the command is entered Hence a command entry can be cancelled anytime before the delimiter is entered by committing an error That is enter any character that is not legal for the expected entry The monitor detects this error aborts the command displays symbol and returns to command entry mode 4 4 MONITOR COMMANDS Each command described in this chapter consists of a single character followed by apropriate parameters and data These commands are summarized in Table 4 1 and are described in detail in the following sections In the table as well as in the subsequent descriptions the following notation is used A capital letter indicates a command mnemonic a indicates an optional parameter a a b indicates either a or b to be entered Oda 3 gt gop MPS 85 3 User s Manual 1 34 b indicates the nature of a 1 or 2 byte hex value to be enterered by the user as a parameter or data lt CR gt indicates
46. e then the file cannot be opened At sign on the following message is displayed MPS 85 Text Editor Vx y D Delete I Insert L List R Replace X Exit If user wants to load a text file from the audio cassette then respond to the LOAD prompt with the name of the file followed by a lt CR gt the audio cassette interface player is installed prior to this Now depress the PLAY key on the cassette player After loading the text the file parameters and the Editor prompt will be displayed Starting Address SSSS Ending Address EEEE Buffer End Now the user can specify a value greater than the present file end address for future expansion while editing But a response of lt CR gt only will not allow the user to expand the file while allowing other editing features In case you do not want to load from the audio cassette then it can be skipped by a lt CR gt Oda 3 gt gop MPS 85 3 User s Manual 1 89 Text Buffer 9000 A7FF Starting Address Now type in the Starting address of the buffer the system will respond with Ending Address Now type in the Ending address of the buffer Then the system will enter the editor mode with the editor prompt gt displayed on the next line NOTE The default value for the buffer start and end is enclosed in the brackets and can be chosen by skipping both the prompts gt is the Editor command prompt The individual commands with the proper syntax are expl
47. e on the audio tape has got corrupted 9 2 DISASSEMBLER 9 2 1 Main Features This module is invoked if user choice is D from the main menu The following sign on message is displayed with the prompt MPS 85 Disassembler Vx y Program Starting Address Type in the starting address for the assembled code that has to be disassembled Now user will be prompted with Oda 3 gt K gop MPS 85 3 User s Manual 1 92 Ending Address After user typed in the ending address it will prompt you for the Label starting address as Label Table A800 AFFF Starting Address And this will be followed by the prompt for the ending address NOTE 1 If the ending address lt starting address it will prompt you all over again 2 The default location of the label table is enclosed in the brackets After the correct data for the above are given system starts execution and display the following message Starting Pass 1 And then followed by the message Starting pass 2 Then it displays the display column headers as ADDRESS CODE LINE LABEL MNEMONIC OPERAND The disassembler code is then displayed according to the above format The display can be halted at any point by CTRL S and restarted by typing any other key At the end it will display End of Disassembly And the control will be returned to the main menu Oda 3 gt K gop MPS 85 3 User s Manual 1 93 9 2 2 ERROR DESCRIPTION Label Table Exhausted This is displayed before
48. e this value with the values shown in Table 5 2 in chapter 5 on Hardware Example 5 If your objective is to display a numerical value only as in the above example a much simpler way would be to use the routines UPDAD UPDDT The above program can be rewritten as follows if we use the routine UPDDT Oda 3 gt gop MPS 85 3 User s Manual 1 79 LOCATION CONTENTS LABEL MNEMONIC COMMENTS 8800 CD BA 03 LOOP CALL RDK BD Get key code 8803 06 00 MVI _ B 00 No Dot 8805 32 Fl 8F STA 8FF H Store key code in sreserved location 8808 CD 4C 04 CALL UPDDT sto Display it 880B C3 00 88 JMP LOOP Example 6 This example flashes the two fields of display alternately This program uses a subroutine to produce delay between the displays LOCATION CONTENTS LABEL MNEMONIC COMMENTS 8800 3E 00 AGAIN MVI A 00 Use address field 8802 06 00 MVI B 00 No dot 8804 21 40 88 LXIH 8840H Use character string starting at location 8840 H 8807 CD 89 03 CALL OUTPUT _ and display Fire 880A 3E 01 MVI A OI Use data field 880C 0600 MVI B 00 No dot 880E 21 44 88 LXI H 8844H Character string Starts at 8844 H 8811 CD 89 03 CALL OUTPUT Display blanks in data field 8814 CD 31 88 CALL DELAY Introduce a delay 8817 3E 00 MVI A 00 Use address field 8819 06 00 MVI B 00 No dot 881B 21 46 88 LXI __H 8846H display HELP i
49. el fc lt T 85 2 TESTPAC H z Browse Downloading Download At 8146 in Progress CONNECTED H NUM CAPS COM2 9600 Tisan BOC lt i inbox cut a e bombs FORMED 2 Click on Browse tab select the file which user wants to download and clock on OK button 3 After downloading the program user can execute the program without entering command window also For that go to RUN menu and select SET PC option then observe the following dialog box Od ceo MPS 85 3 User s Manual 1 66 BB Files View Run Wind CONNECTED H NUM CAPS COM2 9600 0000 CETE ES Tm z wrons D E 4 In that Set PC dialog box user can give the program starting address and click on OK button Now go to RUN menu and select RUN then the program will execute and user can see the output 5 Otherwise go to view menu and select command window option then user can find the following dialog box Od ceo MPS 85 3 User s Manual 1 67 3 1 Command Window gt 7 MPS 85 SERIAL MPS 85 SERIAL NPS 85 SERIAL HPS 85 SERIAL NPS 85 SERIAL MPS 85 SERIAL Command stent A i TBwinasa windows Div 03 mes 653 Microso Word A PSES Micrsot Word 6 Here user can give GO command to execute the program MONITOR MONITOR HONITOR MONITOR MONITOR MONITOR vi v1 ut ut U1 v1 BIA 457M OAD MPS 85 3 User s Manual ZA 1 68 7 6 2
50. en inserted you can use the EXAM MEM command to observe the contents of the locations 8830H to 883DH 883A 3 883D Also note that the address reference for the JNZ instruction has changed from 8831 to 8834 After inserting the instruction and after examining the program suppose you discover that you have two extra instructions POP D and POP H You can delete these instructions by the following key sequence Key Pressed Display Comments Address Field Data Field RESET UPS 85 System Reset DELETE 8830 Current LOW LIMIT You do not want to change it So press NEXT NEXT 883A Current HIGH LIMIT 8 0008 New HIGH LIMIT 8 0088 3 0883 D 883D NEXT Enter LOW DELETE ADDRESS Note that POP D is now at 883BH and not at 8838 H 8 0008 8 0088 3 0883 B 883B NEXT Enter HIGH DELETE Address 8 0008 8 0088 3 0883 C 883C EXEC The two bytes are deleted Command prompt appears To check the operation use EXAM MEM key to observe the contents location 8830H to 883BH They should be C5 01 30 OB 78 B1 C2 34 88 C1 C9 OAD MPS 85 3 User s Manual QUO 1 30 3 5 USER DEFINED FUNCTION MPS85 3 trainer has two command keys whose functions can be defined by the user These keys labeled F1 amp F2 are available in addition to the standard command keys described already When the user defined function key F1 is pressed monitor t
51. enu and select options in the WIN853 window List of parameters and their current values will appear on the dialog box Select the desired parameter with the help of arrow keys The parameters allowed to be set are Communication Port suitable COM Baud Rate 110 150 300 600 1200 2400 4800 9600 Number of Data bits 7 or 8 Number of Stop bits lor 2 and Parity NONE ODD EVEN After selecting the desired values click Ok in the following dialog box Otherwise click on CANCEL to ignore the values Table 7 1 shows details of the integer values and corresponding parameters Commn Baud Data Stop Parity Port intl Rate int2 Bits int 3 Bits int 4 int COM1 0 110 0 fi 0 1 0 odd 0 COM2 1 150 1 8 1 2 1 none 1 300 2 even 2 600 3 1200 4 2400 5 4800 6 9600 7 Table 7 1 7 6 4 HELP On line help is available for all MPS 85 3 monitor commands and specific commands of WIN853 Get Help facility by selecting help option in the window A menu of commands are displayed from which the desired command can be selected and associated information about that command is displayed These options are explained in detail in online help of WIN853 WIN853 hIp Note Whenever the command window is full it is recommended to clear the command window with CLS command Otherwise display will become a little bit slow TROUBLE SHOOTING 1 Check the PC Serial Port working condition 2 Check the Serial Cable working condition 3 Check MPS 85 3 Trainer
52. er SET statement or set permanently by a EQU directive The label shouldn t have been defined earlier through anything else other than another SET statement g EQU Equate label to value Syntax Label EQU expression This differs from the SET directive in the fact that the label that has been defined by a SET directive temporarily can be defined permanently by this statement Any label that has been defined earlier by any means except by a SET statement cannot be defined again by this statement h END End assembly Syntax END This instructs the assembler to end processing at the end of the two passes The assembler inserts an END statement at the end of the file if it is missing 9 3 5 ERROR DESCRIPTION D Error Messages Oda 3 gt K gop MPS 85 3 User s Manual 1 99 1 In the case of the number of errors during the Pass 1 exceeding 85 eighty five the normal assembler display format is changed and only an error listing is produced that includes only invalid lines detected during the Pass 1 The Pass 2 is not started at all and the assembly is aborted 2x If the file doesn t contain the EOL EOF marker sequence ODH followed by 1AH then it displays IMPROPER FILE And aborts assembly 3 If the END statement is absent then it displays Missing END statement at the end of Pass 1 and carries on to the Pass 2 This is not a fatal error 4 If the symbol table space is not sufficient and the label space gets exh
53. er is initialised by the system firmware to provide proper baud clock based on the settings of the DIP switch as shown below Baud rate selection S3 S2 S1 Baud rate ON ON ON 110 ON ON OFF 300 ON OFF ON 600 ON OFF OFF 1200 OFF ON ON 2400 OFF ON OFF 4800 OFF OFF ON 9600 OFF OFF OFF 19 200 Default factory setting 2 1 3 MEMORY SELECTION MPS 85 3 has three 28 Pin sockets labelled U1 U2 U3 for memory Two of these sockets are populated and the third one is for expansion by the user System firmware 16K bytes is supplied in a 27128 EPROM at the socket U1 32K bytes of static RAM is provided bya 62256 at the socket U3 The other socket U2 is for user expansion This socket can be configured through jumper settings JP1 and JP2 to accept 2732 2764 or 27128 to provide 4K 8K or 16K bytes of ROM Alternatively it can accept 6264 RAM to provide 8K RAM As installed at the factory the jumpers are set for 27128 option But the socket is left unpopulated The configuration can be set as shown below Oda 3 gt 3 gop MPS 85 3 User s Manual 1 5 Device Address Range Jumper Setting 4K EPROM JP2 BC 4000H 4FFFH 2732 5000H 5FFFH 6000H 6FFFH 7000H 7FFFH 8K EPROM 2764 4000H 5FFFH 6000H 7FFFH 6264 8K RAM 4000H SFFFH 6000H 7FFFH 27128 16K EPROM JP2 AB 4000H 7FFFH Default factory setting 2 1 4 INTERRUPT AND RE
54. etic operator OAD MPS 85 3 User s Manual 1 96 QUO 1234d 10H 1101B more than two terms in the expression If the label is undefined then an expression error occurs 9 3 3 Syntax of the Source Line a Label Field The length of the label has been restricted to 6 six to save the limited address space for the symbol table The characters allowed in the label are A Z and 0 9 In addition to this And symbols are allowed as the first character only Also the label should not start with a numeral 0 9 The label should be followed immediately by a colon Even mnemonic names can be used in the label field There is no restriction as to its placement Dummy labels are also allowed b Mnemonic Field The mnemonic or the pseudo opcodes can be placed immediately after the colon or after the label if a label is present or it can be placed anywhere c Operand Field The operand can also be placed anywhere and there can be tabs and spaces between the different segments of the operand d Comment Field The field is distinguished from the others by a semicolon preceding it Any character after the first occurrence of the semi colon including the semi colon is not processed and is considered as a part of the comment 9 3 4 Assembler Directives a ORG Origin Oda 3 gt K gop MPS 85 3 User s Manual 1 97 Syntax ORG expression This directive defines the location counter with respect to which
55. gt new data gt gt lt CR gt OPERATION 1 Enter S followed by the address of the memory location to be examined and then enter a comma The monitor will now output the contents of that location followed by a dash Note that in Serial monitor mode a is always a prompt for data entry while a is the prompt for command entry 2 To modify the contents of this location the user can enter the new value now 3 Enter a comma either immediately after the prompt by the system or after the entry of a new value to examine modify the next sequential location A carriage return instead of the comma terminates the command and returns the monitor to the command entry mode ERROR CONDITIONS 1 Trying to modify the contents of non existent or ROM locations Example 1 Examine the ROM location 11H S11 8F lt CR gt Example 2 Examine a series of RAM locations starting at 8820H and modify the contents of the location 8822H 88820 XX 8821 XX 8822 XX AA lt CR gt Oda 3 gt 2 gop MPS 85 3 User s Manual 1 36 Example 3 S0 F3 FF When you try to modify the contents of a ROM location the monitor displays the error sign a question mark and returns the command prompt To see that the contents of the addressed location remain unaltered you can use the S command again to examine the location OH 4 4 2 D DISPLAY MEMORY COMMAND FUNCTION This command is used to display the contents of a block of me
56. he error message along with command prompt character was displayed You can repeat the above sequence of keys to see that the content of this location is unaltered 3 4 2 EXAMINE MODIFY REGISTER COMMAND FUNCTION The examine Register Command is used to examine and optionally modify the contents of any of the 8085 s registers FORMAT EXAM REG lt reg key gt lt data gt NEXT EXEC OPERATION l To use this command press the EXAM REG key when prompted for a command Now the display is cleared and a decimal point appears at the right edge of the address field However unlike in EXAM MEM command this prompt now means that a register name entry is required Thus the next hexadecimal key board entry will be interpreted as a register name TABLE 3 2 PROCESSOR REGISTERS Register Name Register identifier Display abbreviation Key Register A A A Register B B B Register C C C Register D D D Register E E E Flags Register F F Interrupt Mask 3 1 I Register H 8 H H Register L 9 L L Stack Pointer High byte 4 SPH SPH Stack Pointer Low byte 5 SPL SPL Program Counter High byte 6 PCH PCH Program Counter Low byte 7 PCL PCL OAD MPS 85 3 User s Manual 1 15 QUO FORMAT OF INTERRUPT MASK I 0 0 0 0 TE M75 M6 5 MS 5 nterrupt Masks Interrupt Enable Flag FORMAT OF THE FLAG BYTE F S Z X AC X P X C Sign Zero Auxilary Parity Car
57. he location counter is not affected by its presence Oda 3 gt K gop MPS 85 3 User s Manual 1 95 The display can be halted at any point by CTRL S and restarted by any other key At the end of the assembly the control is transferred back to the main menu 9 3 2 Expression Syntax The assembler allows expressions with a maximum of two terms separated by the following symbols that allow arithmetic operation like addition subtraction multiplication and division respectively The terms separated by the arithmetic operators can either be a label or a number The number must be followed by the number system identifier except in the case of a decimal number where the absence of an identifier also signifies decimal number The identifier allowed are the following B Binary number O Octal number D Decimal number H Hexadecimal number In the case of binary numbers the last 16 binary digits are evaluated For decimal and the hexadecimal numbers the last 4 digits are considered whereas in the case of octal numbers the last 5 digits are taken into account Example of valid expressions LABEL1 110101110001101101B LABEL LABEL2 110111B 8642H 1234H 123D 1000 LABEL 1 Examples of invalid expression LABEL1 Presence of a operator without the second term 1211B 2 is not a binary digit 1210T number system not recognised LABELI LABEL2 arithmetic operator not recognised 1015 LABEL1 missing arithm
58. ile there are two ADD A instructions after MOV B A instruction our code sequence has only one ADD A instruction After opcode 47H in location 8805H there should be 87H 87H and then 80H but we have only one 87H and then 80H So instead of multiplying MSD by 10 we multiplied it by 6 4 2 To correct this we must insert an instruction of one byte length ADD A at location 8807 H We can use the INSERT command for this purpose The required key sequence would be INSERT lt 8800 gt NEXT lt 880C gt NEXT lt 8807 gt NEXT lt 1 gt NEXT lt 87 gt EXEC Now using EXAM MEM command observe the contents of the locations 8800H through 880DH and verify that the program has been entered correctly Now execute it Examine the location 8842H Fine we get the correct result of 2D Example 3 8085 has no instruction for multiplication One simple way to implement multiplication is by repeated addition Here if you want to multiply m by n then you clear the result and add the multiplicand m to the result n times where n is the multiplier Thus 2 x 3 is implemented as 0 2 2 2 6 The following program multiplies any two one byte numbers but assumes that the numbers are unsigned Location Contents Label Mnemonic Comments 8800 OE datal MVI C multiplicand Initialize Reg C 8802 1E data 2 MVI E multiplier Initialize Reg E 8804 21 00 00 LXI H 0000H Clear the HL Pair 8807 7B MOV A E Save the multiplier in A
59. ils 2 2 1 INSTALLATION PROCEDURE FOR SERIAL MODE OF OPERATION a b c d e g Select serial mode of operation Ref Section 2 1 1 Select desired baud rate Ref Section 2 1 2 Select interrupt sources if required Ref Section 2 1 4 Select memory configuration if needed Ref Section 2 1 3 Connect MPS 85 3 to the Host PC through RS 232C cable Appendix E describes the RS 232C interface requirements over the connector J6 Refer appendix C for locating the connectors If a host PC is being used turn on the host PC and execute the driver program Ref Chapter 7 for details Connect the power supply of required capacity to MPS85 3 and turn ON the power Press the RESET Key on MPS 85 3 Now the following sign on message should appear on the console MPS85 3 Serial Monitor V 1 1 V 1 1 indicates version 1 and revision 1 The sign on message is followed by the command prompt in the next line Now MPS85 3 is ready for operation in serial mode Oda 3 gt gop MPS 85 3 User s Manual 1 7 NOTE The keyboard display module will display SErIAL 2 2 2 NO RESPONSE IN SERIAL MODE If there is no response from MPS 85 3 in serial mode after installing it as described in the previous section a Check the power supply connections and voltage levels b Check the RS 232C cable connections at both the ends Appendix E describes the interface in detail c Check the handshake signals of RS 232C inte
60. itialize the parameters multiplicand and multiplier and use the single step command to step through the program After executing the first three instructions check the registers C E H and L and observe their contents to be O K Now step through the next instruction Reg A should be equal to the multiplier 1AH It is Now step through the instructions until JMP instruction checking the register contents after each instruction After stepping through the JMP instruction at the location 880CH we come again to the first instruction of the loop Step through it Now Reg A should contain 19H 1AH 1 But what is it containing It is still LAH though we have decremented the E register which is holding the multiplier value Checking E register shows that the multiplier has indeed been decremented as Reg E now contains 19H So the culprit must be the MOV A E instruction As it is logically the correct instruction the error must be one of coding and we must have done a poor job while desk checking the opcodes Looking up the opcodes we find that indeed instead of entering 7BH opcode for MOV A E we entered 79H opcode for MOV A C in location 8806H Thus the multiplier is never found to be zero and an infinite loop occurs Correct this opcode and run the program again Now it works This rather trivial example was used only to illustrate the use of the single step command in debugging the programs With experience the user will certainly find many mo
61. ity Timer 1 11H Timer 1 is used for baud clock generation Timer 2 12H Timer 2 is available to user The signals are available on connector J4 Control Port 13H 8251A at U9 Programmable Communication Interface Data Port 20H Used for implementing serial communication Command port 21H 8279 at U8 Programmable Keyboard Display Interface Data Port 30H Used for implementing Command Port 31H Keyboard Display interface DIP Switch 50H Used for baud and mode selection Oda gt gop MPS 85 3 User s Manual 1 45 5 5 KEYBOARD DISPLAY INTERFACE The Keyboard Display section of MPS 85 3 is controlled by 8279 The port addresses are given in section 5 4 The 8279 is configured for the following operation mode e Encoded scan keyboard with 2 key lock out e 8 digits 8 bit left entry display The keyboard reading is implemented by polling the command status port of 8279 User can read the keyboard in interrupt driven mode by shorting the jumper JP5 AB and by writing suitable RST 5 5 service routine Refer sec 2 1 4 The codes assigned to the keys of the on board keypad are listed below TABLE 5 3 Serial No also the No Key Corresponding code shown in drawings 1 0 00H 2 1 01H 3 2 02H 4 3 1 03H 5 4 SPH 04H 6 5 SPL 05H 7 6 PCH 06H 8 7 PCL 07H 9 8 H 08H 10 9 L 09H 11 A OAH 12 B OBH 13 C OCH 14 D ODH 15 E OEH 16 F OFH 17 Fl
62. iver Software EPROM Programming Software Audio Tape Interface Driver Software Peripherals 8279 To control 32 keys keyboard and 6 digit 0 5 seven segment LED display 8253 3 Programmable interval timers Timer 0 is used for implementing single step facility Timer 1 is used for generating baud clock and Timer 2 is available to the user Through jumper option user can use Timer 1 also if user does not use it for baud clock 8251 For serial communication supporting all standard bauds from 110 to 19 200 Baud is selected through on board DIP switch 8255 Two numbers are available to user giving 48 programmable I O lines OAD MPS 85 3 User s Manual 1 2 QUO Interface Signals CPU BUS _ Demultiplexed and buffered TTL compatible signals brought out to two 26 pin ribbon cable spectra strip type connectors Parallel I O 48 lines 2 X 8255 of TTL compatible bus brought out to two spectra strip type ribbon cable connectors Serial I O RS 232C with standard MODEM control signals through on board 9 pin D type female connector Interrupts All interrupts except TRAP used for single step implementation are available to user Power Supply Optional 5V 0 1V 3A 12V 1 0V 250mA 12V 1 0V 100mA 30V 2 0V 100mA Oda 3 gt gop MPS 85 3 User s Manual 1 3 CHAPTER 2 CONFIGURATION AND INSTALLATION 2 1 CONFIGURATION OF MPS 85 3 MPS 85 3 Microprocessor trainer is versatile and
63. l adjust only memory references This may necessiate further adjustments as shown in the following example Example 10 Consider the following program which outputs 4 characters stored in a table to the keyboard display controller 8279 LOCATION CONTENT LABEL MNEMONIC 8800 21 OE 88 LXI _H 880EH 8803 OE 04 MVI C 04 8805 7E D10 MOV AM 8806 D3 30 OUT DAT79 8808 23 INX H 8809 0D DCR C 880A C2 05 88 JNZ D10 880D EF RST 5 880E 37 37 60 E3 DB 37H 37H 60H E3H Assume you want to relocate the program to start from 8820H and you want to move the program as well as the table of 4 bytes which starts at 880E H Now if you use BLKMOVE command then write the program fragment to relocate as in Example 9 you will have all memory references properly adjusted But the first instruction will still be 21 OE 88 In otherwords though the table has been moved from 880EH to 882EH the value loaded into H L register pair will remain unaltered This is because of the fact that as already noted RELCT routine adjusts only memory reference address and the instruction LXI H value does not involve memory reference Hence you have to adjust such values after relocation Summarizing the example if constant data is being moved reference to such data items must be adjusted by the user Oda 3 gt gop MPS 85 3 User s Manual 1 87 CHAPTER 9 EDITOR ASSEMBLER 9 0 INSTALLATION PROCEDURE e Set MP
64. lect one From the Existing Groups list Program Group 5 Select the Program Group Default ESA Trainers Click Continue and then observe the following dialog box 2 Windows Driver for MPS 85 3 Trainer Setup Ea Destination File C WINDOWSISYSTEMIRICHTX32 0CX 6 In some cases user will find the following Dialog Box which will indicate the over writing of the existing files Oda 3 gt gop MPS 85 3 User s Manual 1 60 Yersion Conflict E3 file being copied is older than the file currently on your system It is recommended that you keep your existing file File name C Program Files WIN8S3 Help hip Description Your version Do you want to keep this File 7 Click Yes to keep the old file Click No to install the new file Click No to All for the remaining files also 8 Then finally observe the following dialog box which will indicate the completion of installation Windows Driver for MPS 85 3 Trainer Setup 9 Click OK to complete the installation 7 4 UNINSTALLATION PROCEDURE 1 Go to the Control Panel from Start Menu Settings Select Add Remove Programs option User will see the following Dialog Box Oda 3 gt gop MPS 85 3 User s Manual 1 61 Add Remove Programs Properties Ea xf Install Uninstall windows Setup Startup Disk To install a new program from a floppy disk or CD ROM drive click Install aE The following software can be automatically removed
65. mmand When this key is pressed the display is cleared and a dot appears at the right edge of the address field indicating that an address entry is required Enter the memory address of the byte to be examined This value is displayed in the address field of the display After entering the address value press the NEXT key The data byte at the addressed memory location will be displayed in the data field and a decimal point a dot appears at the right edge of the data field indicating that data can be updated If the contents of the addressed memory location are only to be examined press the EXEC key to terminate the command or press the NEXT key to examine modify the next consecutive memory location or the PREV key to examine modify the previous memory location To modify the contents of an addressed memory location enter the new data from the key board note that data values are evaluated modulo 256 However this new value displayed in the data field is not entered into the addressed memory location till NEXT or EXEC or PREV is pressed ERROR CONDITIONS Error conditions occur while attempting to modify a non existent or Read Only Memory ROM location Note that the error is not detected until the PREV or NEXT or EXEC key is pressed When an error is detected the characters Err are displayed along with the command prompt character in the address field Example 1 Examining a series of memory locations starting from OOOO
66. mory FORMAT D lt Start address gt lt end address gt lt CR gt OPERATION 1 To use this command enter D when prompted for command entry After entering D enter the starting address of the memory block whose contents are to be displayed then enter a comma enter the end address of the memory block followed by carriage return 2 Now the monitor will output the starting address the contents of the location from this address to the specified end address The display appears in formatted lines with 16 bytes line The number of bytes displayed on the first line are so adjusted that if the second line is present its first location has address with the last nibble as zero Example 1 To display the contents of 5 bytes from location 8800H D8800 8804 lt CR gt 00 01 02 03 04 05 06 07 08 09 OA OB OC OD OE OF 8800 41 42 43 44 31 Oda 3 gt 3 gop MPS 85 3 User s Manual 1 37 4 4 3 M MOVE MEMORY COMMAND FUNCTION This command is used to move a block of data from one area of the memory to another area FORMAT M lt start address gt lt end address gt lt destination address gt lt CR gt OPERATION 1 To use this command enter M when prompted for command entry Follow it with the starting address of the source block to be moved start address a comma the ending address of the source block end address another comma and then the starting address of the area into which the source block is to be moved de
67. n 881E CD 89 03 CALL OUTPUT address field 8821 3E 01 MVI A OI Use data field 8823 06 00 MVI B 00 No dot 8825 21 4A 88 LXI H 884AH Message start 8828 CD 89 03 CALL OUTPUT Display US in data field 882B CD 31 88 CALL DELAY Introduce a delay 882E C3 00 88 JMP AGAIN Repeat the sequence 8831 11 FF FF DELAY LXI D FFFFH 8834 1B DLOOP DCX D 8835 7A MOV A D Oda 3 gt gop MPS 85 3 User s Manual 1 80 8836 B3 ORA E 8837 C2 34 88 JNZ DLOOP 883A C9 RET ORG 8840H 8840 OF 13 14 OE 16 DB OF 13 14 OE 16 10 OE 11 12 16 1610 OE 15 05 11 12 15 05 Enter the program from 8800H to 883AH and enter the data from 8840H to 884BH using the EXAM MEM command Using the GO command execute the program You should see alternate displays of the messages FIrE HELP US The delay between the messages can be changed by altering the value initially loaded into D E register pair in the DELAY subroutine Example 7 This example illustrates the use of KBINT key As explained in chapter 5 on Hardware KBINT key is connected to the RST7 5 pin of 8085 processor Jumper JP7 BC is shorted as factory installed option When this key is pressed control is transferred to a prespecified location in memory 3CH as RST7 5 is a vectored interrupt The monitor has a JMP 8FBFH instruction starting at this location Thus when KBINT key is pressed control first goes to the location 3CH and by execu
68. ntents EXAM REG lt reg key gt lt data gt NEXT EXEC SINGLE STEP Executes a single user program instruction SINGLE STEP lt Start addr gt NEXT lt Start addr gt NEXT EXEC GO Transfers control from monitor to user program Go lt addr gt EXEC BLOCK MOVE Moves a block of data from one portion to another BLK MOVE lt start Addr gt NEXT lt end addr gt NEXT lt DEST ADDR gt EXEC INSERT Inserts one or more instructions in the user program INSERT lt Low limit gt lt High Limit gt NEXT lt Low Insert Addr gt NEXT lt No of bytes gt NEXT lt DATA gt EXEC DELETE Deletes one or more instructions in the user program DELETE lt Low Limit gt NEXT lt High Limit gt NEXT lt Low delete addr gt NEXT lt High Delete addr gt EXEC INPUT BYTE Inputs a byte from the specified port INBYTE lt port address gt NEXT NEXT EXEC OUTPUT BYTE Outputs a byte to the specified port OUT BYTE lt port address gt NEXT lt data gt NEXT lt data gt EXEC Oda 3 gt gop MPS 85 3 User s Manual 3 4 1 EXAMINE MODIFY MEMORY COMMAND FUNCTION This command is used to examine the contents of selected memory locations The contents can be optionally modified if the memory location is in RAM area FORMAT EXAM MEM lt address gt NEXT lt data gt NEXT PREV EXEC OPERATION 1 To use this command press the EXAM MEM key when prompted for a co
69. oad dialog box as follows fa x Files View Run Window Help D Documents and S z Browse e000 3FFF d OK E Uploading Uploading in progress 8088 CONNECTED H NUM CAPS COM2 9600 0000 4 Click on CANCEL button in the upload dialog box after a successful uploading If user wants to append the memory to same uploaded file once again click on OK in the upload dialog box Then user can find the message as follows Od 3 gt 2 ceo MPS 85 3 User s Manual 1 71 Be E Files View Run Window Help ESE WIN853 D Append to the previous file CONNECTED H NUM CAPS COM2 9600 0000 Msat 2ees kme EW an BE 5 Click on OK to append to previous file and click on CANCEL After this operation user can download the uploaded file as already mentioned above in the 10 6 1 session The following error messages may appear during upload and download due to improper operations 1 File not found 2 Path not found 3 No more files 4 Access denied 5 Invalid file handle 6 Insufficient Disk space 7 Unable to continue upload 8 Colon is not present at the start of the Record 9 Invalid data in source file the following Record 10 Checksum Error in the following Record Od 3 gt k ceo MPS 85 3 User s Manual 1 72 7 6 3 COMMUNICATION Communication parameters can be set during the session by pressing Ctrl O or go to view m
70. oard peripherals The clock out from CPU is buffered by 74 LS 245 at U17 and is available on connector J4 This clock is divided by two by 74 LS 74 at U15 to provide the peripheral clock PCLK The lower address bus is demultiplexed using a 74 LS 373 at U4 and the upper address bus is buffered using 74 LS 245 at U16 The data bus is buffered using a 74 LS 245 at U14 The control signals RD WR IO M ALE INTA HLDA and RST OUT are buffered by 74 LS 245 at Oda 3 gt gop MPS 85 3 User s Manual 1 43 U6 All these buffered signals are available on the system connectors J3 and J4 connector details are given at the end of this chapter The enable of these buffers is controlled by BHLDA signal Thus these buffers are automatically disabled when another bus master gains control through HOLD signal to drive these signals 5 3 MEMORY ADDRESSING MPS 85 3 has three 28 pin JEDEC compatible slots U1 U2 and U3 for accepting memory devices The socket at U1 is populated with a 27128 which contains the system firmware The socket at U3 is populated with a 62256 to provide 32K bytes of static RAM Memory from 8F90H to 8FFFH is utilized by the system and the rest is available to the user The socket at U2 is unpopulated This socket can be configured to accept 2732 2764 27128 via jumper JP2 Refer section 2 1 3 The memory map is as follows TABLE 5 1 Memory Map Device Address Range 27128 at U1 0000 3FFF 62256 at U3
71. odulo 64k or 256 respectively i e only the last four or the last two digits entered will be accepted The RESET key causes a hardware reset and restarts the monitor The monitor displays the sign ON message UPS 85 across the address and data fields of the display Now the monitor will be ready to accept the commands from the user But the monitor does not save the information about the state register values etc of any previous user program However the monitor does not disturb contents of the user portion of the RAM area 3 2 RAM USAGE The system monitor utilizes RAM locations 8F90H to 8FFFH for Storing the System Stack and variables User programs should not disturb this area otherwise the results are unpredictable Oda 3 gt gop MPS 85 3 User s Manual 1 10 3 3 KEYBOARD AND DISPLAY As noted already the display consists of 6 seven segment LED displays separated into two fields The left field called the address field consists of 4 digits and the right field called the data field consists of 2 digits The 32 key keyboard consists of the following groups of keys a Hexpad 16 keys representing the hexadicimal digits 0 through F In the use of the EXAM REG command some of these keys represent register names also as indicated by the legends on the keytops This usage is further explained in the description of the EXAM REG command Further six of these keys serve the functions of command keys also The context of
72. operation defines the meaning of the key Command group 11 command keys two of which are USER DEFINED These commands are in addition to the six commands mentioned above Delimiter group 3 keys NEXT PREV EXEC which serve as the delimiters while entering the commands data System operation keys RESET and KBINT keys RESET key as already noted causes a hardware reset of the system KBINT key is connected to the RST 7 5 input It s use is explained in chapter 8 3 4 MONITOR COMMANDS The keyboard monitor is capable of executing ten individual commands summarized in Table 3 1 Each command is represented by exactly one key with appropriate legend on the keytop The commands are described in detail in the following sections In both the table and individual command descriptions the following notation is used Upper case letters and numbers represent keyboard keys A indicates that A is an optional entry A B indicates that either A or B must be entered A indicates zero or more optional occurences of A lt B gt indicates a 1 or 2 bytes parameter to be entered by the user OAD MPS 85 3 User s Manual 1 11 TABLE 3 1 KEYBOARD MONITOR COMMAND SUMMARY COMMAND FUNCTION FORMAT EXAMINE MODIFY MEMORY Displays Modifies the contents of a memory location EXAM MEM lt add gt NEXT lt data gt NEXT PREV EXEC EXAMINE MODIFY REGISTER Displays modifies 8085 register co
73. ped At the end of the above prompt the assembler begins the assembly After the initialization process the assembler also checks if the source file is a proper text file or not i e occurrence of the end of the file marker 1AH followed by end of line marker ODH The processing is completed at the first occurrence of such a combination The symbol table is created and most of the errors are checked for and detected during the Pass 1 the start of which indicated by the following message Starting Pass 1 This is followed by the message Starting Pass 2 Which indicates the termination of the Pass 1 and the start of the Pass 2 Any error that was found in a line during the Pass 1 is noted and the error code stored This enables the assembler to skip those lines for further processing During the Pass 2 the ultimate codes are generated and loaded at the specified location as per the ORG directive or the RORG directive The value of the location counter the codes the line number and source line is displayed along with the error code for that line if any The format of the displayed lines is as shown below ELLLL CCCCCC NNNN Source Line _ gt Where E is the error code if any LLLL is the current value of the location counter CCCCCC are the object codes generated and loaded NNNN is the current line number Source Line is the complete source line The code field CCCCCC is blank if there is an error in the line and t
74. put to USART Regs A C and flags are affected 0C41H NMOUT Outputs one byte as two hex digits to the Serial I O device Inputs A Byte to be output Regs A B C and flags are affected OB88H PRVAL Gets the ASCII code corresponding to a hex digit Inputs reg C Hex digit Outputs C Corresponding ASCII code Regs B C H and L are affected OB5BH DISPM Displays a string of characters The string should be terminated by character Zero which is not output Inputs HL Starting address of the string of characters Regs A C H L and flags are affected OABAH GETHX Gets 2 or 4 hex digits Inputs None Outputs Carry 1 if valid hex value is received Carry 0 otherwise D Terminator Code BC 4 hex digits or C 2 hex digits All registers are affected 0B34H HILOS Compares two hex values Inputs DE Hex value 1 HL Hex value 2 Outputs Carry 0 if DE gt HL lifDE lt HL Only flags are affected OBE4H VALDG Checks if the character in register C is a valid hex digit Inputs C Character to be checked OAD MPS 85 3 User s Manual 1 55 Outputs Carry 1 if the character is a valid hex digit 0 F Carry 0 otherwise Reg A and flags are affected 0800H SERIAL Invokes serial monitor program OAD MPS 85 3 User s Manual QUO 1 56 CHAPTER 7 COMMUNICATION WITH A HOST PC 7 1 INTRODUCT
75. ransfers control to a prespecified location in RAM 8F90H When the user defined function key F2 is pressed monitor transfers control to a prespecified location in RAM 8F94H Following Power ON Reset the monitor initializes this area with the instruction JMP Err Thus after Power ON Reset if you press the function keys Error message along with the command prompt Err is displayed MAKING USE OF THE FUNCTION KEYS To use the user defined function keys the user must write appropriate instructions in the locations reserved for the user function keys Here is an example to show the use of function keys Note that as only 3 bytes starting from 8F90H are reserved for Fl key the user instruction will generally be a JMP instruction EXAMPLE Assume that the user has written the software for programming a specific type of EPROM Assume that this program is assembled from location 4000H expansion ROM area One way to invoke this routine would be to use the GO command to transfer control to this program The second way is to use the function key Assume that the user has decided to use the key F1 Thus when F1 is pressed the program at 4000H should gain control To do this user can set up a JMP instruction at 8F90H as follows Location Byte value 8F90H C3 8F91H 00 8F92H 40 Now whenever the F1 key is pressed the EPROM programming routine at 4000H gets control of the system Oda 3 gt E gop MPS 85 3 U
76. re ways in which the commands can be combined to develop useful programs Oda 3 gt 2 gop MPS 85 3 User s Manual 1 78 8 3 USE OF MONITOR ROUTINES The user can considerably simplify his program development if he makes suitable use of the several useful routines available in the system Monitor Chapter 6 provides the descriptions and calling addresses of such useful routines available in the keyboard monitor and in the serial monitor The programming examples which follow illustrate the use of monitor routines Example 4 This example waits for the user to press a key and then displays the corresponding internal key code in the data field The program is an infinite loop and to recover from this program you must press the RESET key NOTE The keys RESET and KBINT are not connected to the keyboard controller So the program cannot recognize these two keys LOCATION CONTENTS LABEL MENMONIC COMMENTS 8800 CD BA 03 LOOP CALL RDKBD Get the key code 8803 57 MOV D A Reg D Hex value to be expanded 8804 CD 4F 03 CALL HXDSP Expand the digits 8807 06 00 MVI B 00 No Dot 8809 3E 01 MVI A O1 use data field for display 880B CD 89 03 CALL OUTPUT Display the keycode 880E C3 00 88 JMP LOOP Enter this program using EXAM MEM command and execute it using GO command Whenever a key is pressed any key other than RESET and KBINT keys its internal keycode is displayed and you can compar
77. red in location 8842H The program first multiplies the most significant BCD digit by 10 and then adds the second BCD digit to get the Binary number The multiplication by 10 is implemented as repeated addition 10 xa 8xa 2xa 4xa 4xa 2xa MNEMONIC COMMENTS BCDBIN LXI H 8840H Point to BCD string MOV A M Get most significant BCD digit ADD A MSD x 2 MOV B A Save it ADD A MSD x 4 ADD A MSD x 8 ADD B MSD x 8 MSD x 2 INX H ADD M Add next BCD digit to get binary equivalent INX H MOV M A and store it RST 5 Return to monitor OAD MPS 85 3 User s Manual QUO 1 75 Suppose you decide to hand assemble this program to start from location 8800H Assume we get the following sequence of bytes 21 40 88 7E 87 47 87 80 23 86 23 77 EF Enter these 13 decimal bytes into locations 8800H through 880CH Set up two BCD digits in locations 8840H and 8841H say 4 and 5 Now execute the program using the GO command After the execution of the program control returns to the monitor and a command prompt dash will be displayed Now using EXAM MEM command examine the contents of the location 8842H Surprisingly instead of the expected 2D we find 1D So we should again check the program After going through the program again we find the logic to be correct The next step is to check the coding Now we find fortunately that wh
78. rface d Check the baud rates of MPS 85 3 and the host connected to it e Ifa host PC is the controlling device check that the driver program is running the RS 232C cable is connected to the correct port and that the port is working f Check the configuration of MPS 85 3 again DIP Switch settings jumpers NOTE DIP switch status is read only at power ON reset If you change the settings either press the RESET key or switch OFF and then switch ON the power supply If the problem still persists please contact the manufacturer service center 2 2 3 INSTALLATION PROCEDURE FOR KEYBOARD MODE OF OPERATION a Select Keyboard mode of operation Ref Section 2 1 1 b Set the memory configuration if necessary Ref Section 2 1 3 c Connect the power supply of required capacity to MPS 85 3 and switch ON the power d Press the RESET key of the Keyboard Now the following sign on message will appear on the seven segment display UPS 85 Now MPS85 3 is ready for operation in the keyboard mode Oda 3 gt gop MPS 85 3 User s Manual 1 8 2 2 4 NO RESPONSE IN KEYBOARD MODE If the correct sign on message does not appear in the keyboard mode then check the following items a If the seven segment display is totally blank then check the power supply connections and voltages b If the seven segment display shows random pattern then check the configuration settings once again NOTE DIP switch is read only at power O
79. ry Carry Fig 3 1 FORMAT OF I and F REGISTERS 2 When the hexadecimal key is pressed the corresponding register abbreviation is displayed in the address field and the contents of this register are displayed in the data field and a data update prompt dot appears at the right edge of the data field Table 3 2 defines the 8085 register names the hexadecimal keyboard acronyms the abbreviations appearing in the address field of the display and the sequence in which the registers are displayed The formats of the flag byte F and interrupt mask I are shown in Figure 3 1 a When the register contents are displayed with the data update prompt the contents of this register can be modified if desired To do this enter the new value from the keyboard This new value will be displayed in the data field and the register contents are updated when either the NEXT or EXEC key is pressed 4 After examining and optionally modifying the contents if the EXEC key is pressed the command is terminated If the NEXT key is pressed the abbreviation and contents of the next register according to the order shown in Table 3 2 are displayed and opened for modification Note that the sequence is not cyclic and thus pressing the NEXT key when the PCL is displayed will terminate the command Oda 3 gt gop MPS 85 3 User s Manual 1 16 Key Pressed Display Comments Address Field Data Field RESET UPS 85 System Reset EXAM
80. s Present starting address 8FEB 8FEC Starting address of the program LOLMT 8FED 8FEE Ending address of the program HILMT All the instructions between the starting address and ending address are relocated SFES5 8FE6 Low Limit of the range SADD1 8FE7 8FE8 High Limit of the range DADD1 All memory references to the addresses which are within this range are adjusted Operation of RELCT routine This monitor routine will examine each instruction from starting address to ending address If the instruction is not a memory reference instruction it will proceed to examine the next instruction On the otherhand if it is a memory reference instruction then it will check if the referred address is within the range Low Limit High Limit If it is out of range the instruction is not disturbed Otherwise the Relocation offset is added to the reference address of this instruction For example assume the instruction is 78H MOV A B It will be left undisturbed Suppose the instruction is C2 43 88 JNZ 8843H i e a memory reference instruction Suppose the Low Limit is 8840H and High Limit is 8849H Then 8843 is within this range Now assume Oda 3 gt gop MPS 85 3 User s Manual 1 84 that the offset is 0010H Then it will add 0010H to 8843H and this new value of 8853H will replace 8843H Thus the instruction will now appear as C2 53 88 This process is repeated with all the instructions from Start
81. s step is similar to EXAM MEM command operation Oda 3 gt k gop MPS 85 3 User s Manual 1 26 The monitor inserts the new bytes into the user program and makes appropriate changes to the address references that are to be changed because of the insertion NOTES 1 The monitor treats the entire program segment from LOW LIMIT to HIGH LIMIT as relocatable and adjusts all memory reference Hence if the inserted program fragment refers to locations within itself then care must be taken to see that No of bytes is subtracted from all such references before entering them 2 As the size of the program grows when a number of bytes are inserted the user should ensure that there is sufficient free memory available beyond the current end address of the user program 3 Relocation is explained in detail in chapter 8 on Programming Examples ERROR CONDITIONS 1 Specifying a Low Insert Address value that is greater than the value of the High Limit 2 Trying to insert instruction in non existent or Read Only Memory Example Example on the usage of INSERT command is provided in the next section after describing the DELETE Command 3 4 9 DELETE COMMAND FUNCTION This command is used to delete one or more instructions from the user program FORMAT DELETE lt LOW LIMIT gt NEXT lt HIGH LIMIT gt NEXT LOW DELETE ADDRESS gt NEXT lt HIGH DELETE ADDRESS gt EXEC OAD MPS 85 3 User s Manual 1 27 QUO OPERATION
82. ser s Manual 1 31 NOTES 1 If the user inadvertently uses the locations reserved for the user function key the results of pressing the user defined function key are unpredictable 2 Note that the monitor initializes the location reserved for the key F1 amp F2 keys with the JMP Err instruction following either power ON or RESET Thus if the user writes instructions in these reserved locations subsequently presses the RESET key then instructions will be overwritten OAD MPS 85 3 User s Manual 1 32 QUO CHAPTER 4 SERIAL MONITOR 4 1 INTRODUCTION This chapter describes the commands supported by the Serial Monitor Program The Serial Monitor allows MPS 85 3 to be operated froma host PC connected through RS 232C serial interface Refer to chapter 5 on Hardware and Appendix E on RS 232C connector Details The trainer must be configured for serial mode of operation as described in section 2 2 1 When the system enters serial mode of operation the sign on message MPS 85 3 SERIAL MONITOR V 1 1 is displayed the current version number and the revision number on one line and a period on the next line indicating that the monitor is ready to accept commands from the user With the exception of RESET and KBINT keys the keyboard is completely disabled 4 2 RAM USAGE The system monitor utilizes RAM locations from 8F90H to 8FFFH as scratch pad area for system stack and variables User programs should not alter this area
83. ster Memory Dump Download Upload Run single step breakpoints watch windows Memory modification icons etc Note Whenever the command window is full it is recommended to clear the command window with CLS command Otherwise display will become a bit slow 7 6 OPERATION DETAILS The complete command set of the MPS 85 3 is transparent and is fully supported by WIN853 Refer chapter 4 for the monitor mode commands Click on help icon in the WIN853 dialog box for help In addition WIN853 supports the file download file upload and other commands which are explained below NOTE During parameter entry the system expects the alphabetic characters to be in upper case However WIN853 driver is not case sensitive So Keyboard with CAPSLOCK ON is not required 7 6 1 DOWNLOAD OPERATION This feature allows downloading the contents of an object code file into the memory of MPS 85 3 The object code file must be a HEX file with records in INTEL 8 Bit HEX format Refer to the relevant INTEL manuals for the definition of INTEL 8 Bit HEX format Most of the cross assemblers for 8085 do produce object code files which are HEX files with records in INTEL 8 Bit HEX format 1 To perform download operation click on download button or go to file menu and choose download option in the WIN853 dialog box Then observe the following dialog box OAD gt gon MPS 85 3 User s Manual 1 65 m x Files view Run Window H
84. stination address Now enter the carriage return This operation moves the contents of memory locations from start address to end address to consecutive memory locations starting from the destination address ERROR CONDITIONS 1 Specifying an end address value which is less than the value of the start address pA Trying to move data into non existent or Read Only Memory locations EXAMPLES Example 1 Move the contents of the locations 800H through 80FH to the memory block beginning at 8840H M 800 80F 8840 lt CR gt Example 2 M 800 80F 200 lt lt CR gt After executing this command the prompt sign will come but the data will not be moved to the ROM Location Oda 3 gt 3 gop MPS 85 3 User s Manual 1 38 4 4 4 C COMPARE COMMAND FUNCTION Compare command can be used to compare the contents of one memory block with the contents of another memory block FORMAT C lt start address of block1 gt lt end address of block1 gt lt Start address of block 2 gt lt CR gt OPERATION 1 To use this command enter C when prompted for command entry Then enter starting address of the first block a comma ending address of the first block another comma and then the starting address of the second block followed by the carriage return 2 The monitor now compares the contents of location beginning at start address of block1 with the contents of location beginning at start address of block2 This process
85. tails of which are given below These routines can be used to considerably simplify the program development work NOTE User should as a general rule save the registers of interest before calling the monitor routines and restore them after returning from the monitor routines 6 1 KEYBOARD MONITOR ROUTINES ACCESSIBLE TO USER Calling Mnemonic Functions Address 0440H UPDAD Updates Address field of the display The contents of the locations CURAD 8FEFH amp 8FFOH are displayed in the address field The contents of all the CPU registers and flags are affected If Reg B 1 dot at the right edge of the field if B 0 no dot 044CH UPDDT Updates Data field of the display The contents of the location CURDT 8FF1H are displayed in the data field The contents of all CPU registers and flags are affected If Reg B 1 dot at the right edge of the field if B 0 no dot OAD MPS 85 3 User s Manual QUO 1 53 0389H OUTPUT Outputs characters to display The parameters for this routine are as follows Reg A 0 Use address field Reg A 1 Use data field Reg B 1 Dot at the right edge of the filed 0 No dot Reg HL Starting address of character string to be displayed 02BEH CLEAR Clears the display This routine blanks the entire display field Parameter is Reg B 1 dot at the right edge of the address field 0 No dot 04ADH HILO Computes the difference between two 16 bit v
86. the last byte into the location 8808H press the EXEC as the delimiter Note that EXEC is only a delimiter key and is not used for executing the user program The command to be used for executing user programs is the GO command Using this command execute the above program After Oda 3 gt gop MPS 85 3 User s Manual 1 74 execution control returns to the monitor Note that this happens because of the RST 5 instruction When control returns to the monitor via the RST 5 instruction the monitor first saves the complete user context Now use the EXAM REG key to observe the contents of the registers B and C They will be 22 and 82 Using the EXAM MEM command observe the contents of the location 8840 H to be 22 H indicating the successful execution of the program Now press the RESET key and observe the contents of the locations 8808H and 8840H The contents remain undisturbed Pressing the RESET key does not disturb the user portion of the RAM But now examine the B and C registers It is likely that they will not contain the values 22H and 82H If you press the RESET key user register values are not guaranteed to remain unaltered Example 2 The following program converts two BCD digits stored in memory to a binary number and stores the binary number in memory It is assumed that the most significant BCD digit is at the location 8840H and next BCD digit is in the next location i e in 8841H The equivalent binary number is to be sto
87. the lines following this statement are to be assembled With the absence of this the location counter takes the starting default value of 0000H Multiple ORG statements are allowed b RORG Relocatable origin Syntax RORG expression This defines the loading pointer with respect to which the object codes will be loaded The loading pointer takes the value of the location counter if no RORG statement is present Multiple RORG statements are not allowed c DS Define Storage Syntax Label DS expression With this directive the assembler allocates free spaces in the memory the number of bytes allotted is evaluated from the expression The location counter and the loading pointer are incremented by the value of the expression d DB Define byte Syntax Label DB expression OR Label DB ASCII string Using this a specific byte or a string of ASCII characters can be loaded into the memory The expression should evaluate to a value less than or equal to OFFH ie Of one byte length e DW Define word Oda 3 gt K gop MPS 85 3 User s Manual 1 98 Syntax Label DW expression OR Label DW Two ASCII characters This allows loading of two bytes into the memory with the lower byte being loaded first always f SET Set label to value Syntax Label SET expression Here the label will be given a value obtained from the expression This value is temporary and can be changed temporarily again by anoth
88. ting the instruction there comes to location 8FBFH In this region also there are not many bytes available for a service routine so we will write a further JMP at 8FBFH to user RAM area and in that area we must write the service routine The program described below is a random number generator The main program consists of a simple loop to increment a one byte counter The count after reaching FFH become 0 again with one further increment and thus is always a value between 0 and FFH Whenever the user presses the KBINT key the interrupt service routine fetches the counter value masks off the most significant 6 bits displays the value thus the number displayed is always 00 01 02 or 03 and returns to the main program which continues with updating the counter value LOCATION CONTENTS LABEL MNEMONIC COMMENTS 8800 3E OB MVI A 0B Initialise Interrupts 8802 30 SIM Unmask RST 7 5 8803 FB EI Enable Interrupts 8804 AF XRA A 8805 3C LOOP INR A Infinite loop of 8806 C3 05 88 JMP LOOP updating the counter OAD MPS 85 3 User s Manual QUO 1 81 Notice that we must first unmask RST7 5 interrupt using the SIM instruction and then we must enable the Interrupt system using the EI instruction Enter the above program using EXAM MEM command Now we must write the service routine Assume we want to load it from 8820H So we must write a JMP 8820H instruction at location 8FBFH LOCA
89. tion MPS 85 3 does not make use of HOLD signal It is grounded through a 4 7K ohm resistor An off board signal can drive this line via the connector J3 This can be done by opening the jumper connection JP4 A B and shorting JP4 B C As already noted in section 5 2 HOLDA from CPU disables on board buffers Hence user can implement multiprocessor designs for eg DMA systems without any problems 5 11 BUS EXPANSION MPS 85 3 permits easy expansion of the system by providing all the necessary signals on two connectors J3 and J4 The signals are STD bus compatible and thus user can easily expand the capabilities of MPS 85 3 5 12 CONNECTOR DETAILS There are six connectors on MPS 85 3 in addition to the power connector J5 Four of them J1 J2 J3 J4 are 26 pin ribbon cable connectors JI and J2 are connected to parallel I O lines from two 8255s J3 and J4 are used mainly for CPU expansion 9 pin female D type connector J6 provides the signals for RS 232C compatible serial interface The signal definitions on all these connectors are listed below This information is available in Appendix B also CONNECTORS J1 amp J2 PIN NO 8255PIN FUNCTION PINNO 8255PIN FUNCTION ONJ1 J2 ON J1 J2 1 13 PC4 14 19 PB1 2 12 PC5 15 38 PA6 3 16 PC2 16 37 PA7 4 17 PC3 17 40 PA4 5 14 PCO 18 39 PA5 6 15 PCI 19 2 PA2 7 24 PB6 20 1 PA3 8 25 PB7 21 4 PAO 9 22 PB4 22 2 PAL 10 23 PBS 23 11 PC6 HAD
90. tion containing branch instructions Example 1 Enter the program presented as example 1 for the GO command from the keyboard monitor section 3 4 5 You can execute it as shown below G XXXX XX 8800 lt CR gt Example 2 Transfer control to a user program assembled from location 8000H with breakpoints at 804EH and 8124H G XXXX XX 8000 804E 8124 lt CR gt OAD gt gon MPS 85 3 User s Manual 1 42 CHAPTER 5 HARDWARE 5 1 INTRODUCTION This chapter describes the hardware design details of MPS85 3 Appendix A gives the complete schematics Appendix B gives the connector details and Appendix C has the component layout diagram The design details are discussed in the following order a CPU Address Bus Data Bus and control signals b Memory addressing c TO addressing d Keyboard Display Interface e Programmable Interval Timer and Serial Interface f Programmable Peripheral Interface devices g Wait state logic h Interrupts and Hold i Bus expansion j Connector details 5 2 CPU ADDRESS BUS DATA BUS AND CONTROL SIGNALS MPS85 3 uses 8085A CPU operated with a 6 144 MHZ crystal The on board RESET key can provide a RST IN signal to the CPU Alternatively the on board RESET key can be disabled and an external RST IN signal provided via the connector J3 The RSTOUT from CPU is used to reset rest of the system Also this signal is available after inversion on connector J4 for resetting any off b
91. uction byte stored at this location and the data entry prompt character OAD gt gon MPS 85 3 User s Manual 1 41 2 Now if you wish to modify the value of the PC i e the address to which control is to be transferred enter the new value followed by carriage return Now the user context is restored and control is transferred to the program starting at the current value of the user program counter Breakpoints A powerful debugging tool Breakpointing a program is available to the user To use this facility enter a comma after optionally modifying the PC enter a maximum of four breakpoints separated by commas and then enter carriage return Now the control is transferred to the program starting at the current PC value Upon reaching any one of the specified breakpoint addresses control is returned to the monitor Monitor saves the complete user context displays the current PC value and then issues a command prompt NOTES 1 When breakpoint addresses are specified the monitor saves the breakpointed instructions and replaces them with RST 3 instruction When any one of the breakpoints is reached control is returned to the monitor which after saving the registers replaces all the breakpointed instructions with their original values Hence breakpoint addresses must be specified each time a program to be breakpointed is executed 2 Specifying more than one breakpoint address is useful when debugging a program sec
92. ue followed by a valid terminator a comma or the Carriage Return If the terminator is the Carriage Return the command is terminated If the terminator is not the carriage return the next sequential register is displayed and opened for optional modification The sequence in which registers are displayed is also shown in Table 4 2 Note that this sequence is not circular and if a comma is entered after the contents of the last register i e PC are examined modified the command is automatically terminated TABLE 4 2 Abbreviation Register B Register C Register D Register E Flags Register Interrupt Mask Register Register H Oda 3 gt gop MPS 85 3 User s Manual 1 40 Register L Memory Pointer Stack Pointer Program Counter EXAMPLES Example 1 X lt CR gt A FF B EE C 00 D 21 E 34 F A0 07 H 06 L 45 HL 0645 SP 8FE0 PC 8825 Example 2 Examine and alter reg C and then examine reg D XC 52H 34 D 63H lt CR gt 4 4 6 G GO COMMAND FUNCTION The GO command is used to transfer the control of the system from monitor to the user s program with optional breakpoints FORMAT G Start address lt breakpoint address 1 gt lt breakpoint address 2 gt lt breakpoint address 3 gt lt breakpoint address 4 gt lt CR gt OPERATION l To use this command enter G when prompted for command entry The monitor will now display the current value of user program counter the instr
93. us the target address of this JNZ instruction is incorrect It should be 8853 and not 8843 Hence this value must be adjusted suitably In a larger program there might be several such memory references which have to be adjusted This can be done conveniently by using the routine RELCT We have to now set up the parameters for the RELCT routine as shown below Relocation offset As we want to move the program from 8840H to 8850H the offset is 8850 8840 0010H Starting address 8850H and not 8840H Ending address 8859H and not 8849H Low Limit and High Limit As the original program contains reference to addresses in the range 8840 8849H we have to specify this range for our relocation so Low Limit 8840H High Limit 8849H Enter these parameters into the appropriate memory locations using the EXAM MEM Command Now we must CALL the RELCT routine For this purpose we have to write small program Find 4 bytes of unused RAM area say 8C00 8C03H and enter the following program and execute it using the GO command LOCATION CONTENTS COMMENTS 8C00 CD Call the Relocate Routine 8C01 53 8C02 05 8C03 EF Return to monitor Oda 3 gt gop MPS 85 3 User s Manual 1 86 Now you can use EXAM MEM command to examine the locations 8850 8859H and verify that indeed the program has been relocated 8857H location will contain 53H and not the incorrect 43H Note that RELCT routine wil
94. use this command press the INSERT key when prompted for command entry When this key is pressed Low Limit i e the starting address of the program as remembered by the monitor from previous operations is displayed in the address field This value can be changed by the user by entering a new starting address and then pressing the NEXT key If the value displayed is not to be changed simply press the NEXT key Now the monitor displays the assumed High Limit present end address of the user program To change this value enter the new value and press NEXT key Otherwise simply press the NEXT key Now the monitor clears the display and a dot appears at the right edge of the address field indicating that an address entry is required Now enter the Low Insert Address i e the address starting from which insertions are to be made and press the NEXT key Again the display is cleared and a dot appears at the right edge of the address field This time enter the number of bytes to be inserted in hexadecimal followed by the NEXT key The monitor displays the Low Insert Address in the address field and a dot appears at the right edge of the data field prompting a data entry Enter a byte value to be inserted Press the NEXT key if more bytes are to be entered After entering the last byte or after entering a byte followed by the EXEC key the command is terminated and a command prompt appears at the left edge of the display Thus thi

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