DM6810 / DM5810 User`s Manual
Contents
1. 7 4 Interrupt Request Limes tesoro deskas 7 4 8259 Programmable Interrupt Controller 7 4 Interrupt Mask Register IMR 7 4 End of Interrupt EOD Command 7 4 What Exactly Happens When an Interrupt Occurs 7 5 Using Interrupts in Your Programs 7 5 Writing an Interrupt Service Routine ISR 7 5 Saving the Startup Interrupt Mask Register IMR and Interrupt Vector 7 7 Restoring the Startup IMR and Interrupt Vector 7 7 Common Interrupt Mistakes o 7 7 APPENDIX A DM5810 DM6810 SPECIFICATIONS A 1 APPENDIX B CONNECTOR PINASSIGNMENIS2. 1 9 CHAPTER 2 MODULEINSTALLATION e 2 1 Module Installation 2 3 External I O Connections 2 3 ConnectingtheDigital O asas 2 4 Connecting the Timer Coumnter I O coooooocconoonccoonooncoonnoncconnonocononococonnncccnononccnonoocccoonocccononoccoconocccocoonccoonos 2 4 Connectingthe External Interrupt 2 4 Runningthe5810DIAG Diagnostics Program 2 4 CHAPTER 3 HARDWARE DESCRIPTION 3 1 Digital O 3 3 Timer Counters 3 3 CHAPTER 4 MAPPING
3. 4 1 Defining the UUr 4 3 BA 0 Digital I O Port 0 Read Write 4 4 BA 1 Digital I O Port 1 Read Write 4 4 BA 2 Clear IRQ Program Port0 Direction Port 1 Direction IRQ Source Registers Read Write 4 4 BA 3 Read Digital I O Status Program Digital Mode Read Write 4 5 BA 4 Digital VO Port 2 Read Write 0 ss0000ss0s0nssesnnnnssssunsssssnnnssssnnnnssssnnnssssnnnnssssnnnssssnnnnsssnnnnsssse 4 6 BA 5 Digital I O Port3 Read Write 4 6 6 Clear IRQ Program Port2 Direction Port3 Direction IRQ Source Registers Read Write 4 6 BA 7 Read Digital I O Status Program Digital Mode Read Write 4 7 BA 8 Digital VO Port 4 Read Write 4 8 9 Digital I O Port 5 Read Write 4 8 BA 10 ClearIRQ Program Port 4 Direction Port 5 Direction IRQ Source Register
4. o 999999909 1111100 8 q E mm niii nuni c PALL al niin nui Y Aui 29 25 s ibi 25 umnt N E 28 9272117 Movoo ORTA I 111 1177 P4 P16 Interrupt Channel Select Factory Setting Jumper installed IRQ Disabled Theseheaderconnectors shownin Figure 1 2 lets you connect any one of four jumper selectable P14 interrupt sources or any of the 16 digital I O lines in each upto three digital interrupt sources to an interrupt channel IRQ2 through IRQ15 XT channels 2 through 7 arejumpered on P4 and AT channels 10 through 15 arejumpered on P16 DM6810 only In AT computers channels 2 and9 are the same channel To activate a channel you mustinstall a jumper vertically across the desired IRQ channel s pins Only one channel oneither P4 or P16 should bejumpered at anytime Figure 1 2ashows the factory settings This module supports an interrupt shari
5. B 1 APPENDIX COMPONENT DATA SHEETS se C 1 APPENDIX D WARRANTY D 1 14 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 1 3 1 3 2 6 1 74 ListofIllustrations Module Layout ShowingFactory Configured Settings 1 4 Interrupt Channel Select Jumper P4 1 5 Pulling Down the Interrupt Request Lines 1 5 8254 Clock and Gate Sources Jumpers P5 1 6 8254 Circuit Diagram 1 6 Strobe Input Enable Jumper 13 0000000 000000000 1 7 InterruptSourceSelectJumper P14 1 7 Base Address Switch S1 1 8 0 Pull up Pull down Resistor Connections P7 1 9 P2
6. Digitall O The48bit programmable digital I O lines can be used to transfer data between the computerand external devices Six ports Ports 0 1 2 3 4 and 5 each provide eight bit programmable lines which can be independently set forinput or output The digital I O circuitryis containedin three EPLD chips onthe module 16lines per chip grouped as follows Port 0 1 EPLD Port 2 3 EPLD and Port 4 5 EPLD One line per chip can beused to generate a digital interrupt Chapter 5 details digital I O operations and Chapter 7 explains digital interrupts Timer Counters An8254 programmable interval timer provides three 16 bit 8 MHztimer counters to support a wide range of timing and countingfunctions Figure3 2 shows the timer counter circuitry Each 16 bittimer counter has two inputs CLKinand GATE in and one output timer counter OUT Each can be programmed as binary or BCD down counters bywriting the appropriate data to the command word as described in Chapter 4 The command wordalso lets you set up the mode of operation The six programmable modes are 33 Mode0 Model Mode2 Mode3 Mode4 Mode5 Event Counter Interrupton Terminal Count Hardware Retriggerable One Shot RateGenerator Square Wave Mode Software Triggered Strobe Hardware Triggered Strobe Retriggerable These modesare detailed in the 8254 Data Sheet reprinted from Intel in Appendix C ON BOARD CONNECTOR P6 XTAL 8 MHz PIN 1 EXT C
7. DIGITAL GND P3 0 6 62 DIGITAL GND Po 7 63 64 DIGITAL GND 1 7 63 62 DIGITAL GND Po 6 65 69 DIGITAL GND P1 6 65 66 DIGITAL GND 5 67 68 DIGITAL GND P1 5 67 68 DIGITAL GND P0 4 DIGITAL GND P1 4 DIGITAL GND P0 3 DIGITAL GND P1 3 DIGITAL GND P0 2 DIGITAL GND P1 2 DIGITAL GND P0 1 DIGITAL GND P1 1 DIGITAL GND P0 0 DIGITAL GND P1 0 DIGITAL GND 5 VOLTS DIGITAL GND 5 VOLTS DIGITAL GND F2 PS 50 pin connector 50 pin connector F 2 1 P2 P3 and P6 I O Connector Pin Assignments Connecting Digital O The DM5810is designed for direct connection to industry standard opto 22 isolated I O racks and system modules Each digital I O line hasa digital ground as shown in Figure 2 1 For all digital I O connections the high sideofanexternalsignalsourceor destination deviceis connected tothe appropriate signal pinon the I O connec tor and the lowside is connected to the DIGITAL GND A cable to provide direct connection to opto 22 systems the XO50 is available as an accessory from RTD Connecting the Timer Counter I O External connections to the timer counters onthe DM5810 can bemadebyconnecting the highside ofthe external device to the appropriate signal pin on I O connector and the low side to a P6 DIGITAL GND Connecting the External Interrupt TheDM5810canreceive externally generated interrupt signals EXTINT1 throughI Oconnector P2 pin 2 and EXT INT2 through T O connector P3
8. V Save OR 8 Port PortAddress V Save Settingor clearing morethanonebitatatimeis accomplishedjustas easily To clear multiplebitsina port AND thecurrentvalue ofthe port with the value b where b 255 the sum ofthe values of the bits to be cleared Notethatthebits do not haveto be consecutive Example Clearbits2 4 and 6ina port Read inthe current value ofthe port AND it with 171 171 255 22 2 26 andthenwritetheresulting value to the port In C this is programmed as v save v save amp 171 outportb port address v save To set multiple bits ina port ORthecurrentvalue ofthe port with the value b where b the sum ofthe individual bits to be set Note that the bits to be set donot have to be consecutive Example Set bits 3 5 and 7 ina port Read in the current value of the port OR it with 168 168 2 25 2 and then write the resulting value back to the port In assemblylanguage this is programmedas mov al v save or al 168 mov dx PortAddress out dx al Often assigningarangeofbits isa mixture of setting and clearing operations You can setor clear each bit individually orusea faster method offirst clearing all the bits inthe range then setting onlythose bits thatmustbe setusing the method shown above for setting multiple bits ina port The following example shows how this two stepoperationis done Example Assign bits 3 4 and 5 ina portto 101 bits 3 and 5 set bit 4cleared First read
9. Port 0 1 EPLD IRQ Source Register 3 bits 1 and 0 11 D7 D6 D5 D3 D2 D1 Do 00 P1 4 01 P15 10 P1 11 17 Thisregister programs the bit to be used to generate a digital interruptforthe 0 1 EPLD A digital interruptis generated whentheselected bit goes from lowto high interrupt generated on the positive going edge BA 3 Read Digital I O Status Program Digital Mode Read Write Aread shows you whether a digital interrupt has occurred and lets you review the states ofthe other bits in this register Ifbit 7 is high then a digital interrupthas taken place This provides the same status information as BA 17 bit0 Digital Mode Register Bits 0 and 1 Selectthe clear mode initiated by a read write operation at BA 2 orthe control registeryou talk toat BA 2 Port0 Direction Port 1 Direction or Port 0 1 EPLD IRQ Select Register Bit3 Enables strobe input used with P13 header Bit4 Disables enables digital interrupts The IRQ channel is determined bythe jumper setting on P4 Bit5 Setsthe clockrate atwhich the digital lines are sampled when ina digital interrupt mode Available clock sources are the 8 MHz system clock andthe output of the 8254 Counter 1 16 bit programmable clock When a digital input line changes state it must stay at the new state for two edges of the clock pulse 62 5 nanoseconds whenusingthe8 MHzclock before itis recognized andbefore an inter
10. our 4 1 OUT 1 EXT CLK 2 9 0 our 2 OO EXT GATE 0 DIGITAL GND EXT GATE 1 DIGITAL GND EXT GATE 2 DIGITAL GND APPENDIX C COMPONENT DATA SHEETS Intel 62 54 Programmable Interval Timer Data Sheet Reprint APPENDIX D WARRANTY AND RETURN POLICY Return Policy If you wish to return a product to the factory for service please follow this procedure Read the Limited Warranty to familiarize yourself with our warranty policy Contactthe factory for a Return Merchandise Authorization RMA number Please havethe following available Complete board name Board serial number A detailed description ofthe board s behavior List the name of a contact person familiar with technical details of the problem or situation along with their phone and fax numbers address and e mail address if available Listyourshipping address Indicate the shipping method you would like used to return the product to you We will not ship by next day service without your pre approval Carefully package the product using proper anti static packaging Write the RMA number in large 1 letters on the outside of the package Return the package to RTD Embedded Technologies Inc 103 Innovation Blvd State College PA 16803 0906 USA 0 1 LIMITED WARRANTY RTD Embedded Technologies Inc warrants the hardware and software products it manufac tures and produces to be free f
11. The second major concern when writingyour ISR isto makeit as short as possible interms ofexecution time Spendinglongperiods oftimeinyourISR may meanthatother importantinterrupts are being ignored Also ifyou spendtoolonginyourISR it maybe called again before you have completed handling the first run This oftenleads toahangthatrequires a reboot YourISR shouldhavethis structure Pushanyprocessorregistersused in your ISR Most C and Pascal interrupt routines automatically do this for you Putthebodyofyour routine here e Cleartheinterrupt status flag for the source which caused the interrupt Clearjumper selectable interrupt status flag byreading BA 16 Clear the Port 0 1 digital interrupt flag by setting bits 1 and 0 at BA 3 to00 andreading BA 2 Clear the Port 2 3 digital interrupt flag by setting bits 1 and 0 at BA 7 to00 andreading 6 Clear the Port 4 5 digital interrupt flag by setting bits 1 and 0 at BA 11 to 00 andreading BA 10 Issue the EOI command to the 8259 interrupt controller by writing 20H to port20H Popallregisters pushed onentrance Most Cand Pascal interruptroutines automatically do this for you The following C and Pascal examples showwhatthe shell ofyour ISR shouldbe like Only the clear interrupt commandsequence forthe source which caused theinterruptneeds to be included In C void interrupt ISR void Your code goes here not use DOS functions inportb BaseA
12. all 48 I O lines Each portand bit is labeled onthe module P7 connects to theresistors for Port 0 P8 connectsto the resistors for Port 1 and so on The pins are labeled for ground one endand V for 5V onthe other end The middle pinis common Figure 1 9 shows P7 with the factory installed jumpers placed between the common pin middle pinofthe three and the V pin For pull downs install the jumper across the common pin middle pin and G pin To disable the pull up pull down resistor remove the jumper O Ww OD N Ew D7 PORT O Fig 1 9 Port Pull up Pull a Resistor Connections P7 19 1 10 CHAPTER 2 MODULEINSTALLATION The DM5810iseasytoinstallinyourcpuModule or other PC 104 based system This chapter tells you step by step howto installandconnectthe module Afteryou have installed the module and made all ofyour connections you canturnyour systemonandrun 5810DIAG board diagnostics programincluded onyour example software disk toverify that your module is working 2 1 2 2 Module Installation Keep themoduleinits antistatic baguntil you are ready to install itin your cpuModule orother PC 104 based system Whenremovingitfrom the bag hold the moduleatthe edges and do nottouchthe components or connec tors Beforeinstallingthemoduleinyour system check the jumper and switch settings Chapter 1 reviews the factory settings and howto changethem Ifyou needto change any settings refer to
13. disabling the interruptsharing circuit NOTE Whenusing multiple modules sharing the same interrupt only one module should have the G jumper installed The rest should be disconnected Whenever you operate a single module the G jumper should be installed Whenever you operate the module withinterrupt sharing disabled the Gjumper should be removed 14 PROGRAMMABLE INVERT P14 14 IRQ STATUS INTERRUPT BA 17 BIT 3 SOURCE INTERRUPT REGISTER INTERRUPT CLR PORT 0 1 PORT 0 1 DIGITAL DIGITAL CLK INTERRUPT IRQ STATUS BA 17 BIT 0 INTERRUPT REGISTER CLR PORT 2 3 PORTES DIGITAL DIGITAL INTERRUPT IRQ STATUS BA 17 BIT 1 INTERRUPT REGISTER CLR PORT 4 5 FORT 4 5 DIGITAL DIGITAL INTERRUPT IRG STATUS BA 17 BIT 2 INTERRUPT REGISTER CLR Fig 1 3 Pulling D Request Lines 1 5 5 8254 Clock and Gate Source Select Factory Settings See Figure 1 4 This header connector shown in Figure 1 4 lets you select the clock sources for the three 8254 16 bit timer counters Figure 1 5 showsa block diagram ofthetimer counter circuitry to help you inmakingthese connections The clock source for Counter 015 selected by placing a jumper ofthe two leftmost pairs of pins on the header OSC or ECO OSC is the on board 8 MHz clock and ECO is an external clock source which can be con nected through T O connector P6 pin 1 Counter 1 hasthreeclock sources which cascades itto Counter 0 OSC wh
14. in the port and clearbits3 4 and 5 by ANDing them with 199 Then setbits3 and 5 by ORing them with 40 and finally write the resulting value back to the port In C this is programmed as V Save v save amp 199 Vv Save v save 40 outportb port address v save Afinal note Don tbe intimidated bythe binary operators AND and OR and tryto use operators forwhich you have abetter intuition Forinstance ifyou are tempted to use addition and subtractionto set and clear bits in place ofthe methods shown above DON T Addition and subtraction may seem logical but they will not work if you try to clear a bit that is already clear or set a bit that is already set For example you might think that to set bit 5 ofa port you simply need to read in the port add 32 2 to thatvalue and then write the resulting value back to the port Thisworks fine ifbit 5 is not already set But what happens when bit 5 isalready set Bits 0 to 4 will be unaffected andwe can t sayfor sure what happens to bits 6 and 7 but we can say for sure that bit 5 ends up cleared instead of being set A similar problem happens when you use subtraction to clear a bitin place of the method shown above 4 13 4 14 CHAPTER 5 DIGITAL VO This chapter explains the bit programmable digital I O circuitry onthe DM5810 5 1 5 2 TheDM5810has48bulferedbitprogrammable TTL CMOS digital I Olines available for digital control applications These lines are grouped in si
15. is detailedin Chapter 5 Bit6 Reserved Bit7 Readonly digital IRQ status 4 7 BA 8 Digital I O Port 4 Read Write This port transfers the 8 bit Port 4 bit programmable digital input output data betweenthe module and external devices The bits are individually programmed as input or output bywriting to the Port 4 Direction Register at BA 10 Forallbits setas inputs a read reads the inputvalues and awriteis ignored For all bits set as outputs a readreads the lastvalue sent out on the line and a write writes the currentloaded value outto theline Notethatwhen anyreset of the digital circuitryis performed clear chip or computer reset all digital lines are resetto inputs andtheir corresponding outputregistersarecleared D7 D6 D5 D4 D3 02 D1 DO P47 PA6 P44 P42 PAO BA 9 Digital I O Port 5 Read Write This porttransfers the 8 bit Port 5 bit programmable digital input output data betweenthemodule and external devices Thebits areindividually programmed asinputor outputbywritingto the Port 5 Direction Register at BA 10 Forallbits setas inputs a read readstheinputvalues and awriteis ignored For all bits set as outputs a readreadsthelastvalue sentoutonthelineand a write writes the currentloaded valueoutto theline Notethatwhen anyreset ofthe digital circuitryis performed clear chip or computer reset all digital lines are resetto inputsand theircorresponding outputregistersarecleared 27 D
16. the appropriate instructionsin Chapter 1 Notethatincompatiblejumper settings canresultinunpredictable module operation and erratic response TheDM5810comeswithastackthroughP1 connector The stackthrough connector lets you stack another module ontop ofyour DM5810 To install the module followthe procedures described inthe computer manual and the steps below 1 Turn OFF the power to your system 2 Toucha metal rack to discharge any static buildup and then remove the module from its antistatic bag 3 Select the appropriate standoffs for your application to secure the module when you install itin your system two sizes areincluded with the module 4 Holding the module by its edges orient it so that the P1 bus connector s pin 1 lines up with pin 1 ofthe expansionconnector onto whichyouare installing themodule 5 After carefully positioning the module so that the pins are lined up and resting onthe expansion connector gently and evenly press down onthe module until it is secured onthe connector NOTE Donot force the module onto the connector Ifthe module does not readily press into place remove itandtry again Wiggling the module or exerting too much pressurecanresultin damage to the DM5810 0r tothematingmodule 6 After the module is installed connect the cables as needed to I O connector P2 P3 and P6 onthe module When making these connection note that there is no keying to guide you in orientation You must make sure that pin 1
17. you do anythingelse Second just before exiting your ISR you must clear the interrupt status flag ofthe DM5810and write an end of interruptcommand to the 8259 controller Finally when exiting the ISR in additionto popping all the registers you pushed on entrance youmustuse the IRET instruction and nota plain RET The IRET automatically pops the flags CS and IP thatwere pushed when the interrupt was called Ifyou find yourself intimidated by interrupt programming take heart Most Pascal and compilers allowyou to identify a procedure function as aninterrupttype and will automatically add these instructions to your ISR with one important exception most compilers donot automaticallyadd the end of interruptcommandto the procedure you must do this yourself Other than this and the few exceptions discussed below you can write your ISR just like any otherroutine Itcancall other functions and procedures in your program and itcan access global data Ifyou are writing your first ISR we recommend thatyou stick to the basics just something that will convince you that it works suchas incrementing a global variable NOTE Ifyou are writingan ISR using assembly language you are responsible for pushing and popping registers and using IRET instead of RET There are afew cautions you must consider when writing your ISR The most important is do notuse any DOS functions or routines that call DOS functions from within an ISR DOS is not reentrant thati
18. you will be using The IMR is located at I O port 21H The interruptvector you will be using is located in the interrupt vector table whichis simply an array of 256 bit 4 byte pointers andis located in the first 1024 bytes ofmemory Segment 0 Offset 0 You can read this value directly but itis a better practice to use DOS function35H getinterruptvector MostC and Pascal compilers provide library routine for reading thevalue ofa vector The vectors for the hardware interrupts are vectors 8 through 15 where IRQOuses vector 8 IRQ1 uses vector 9 and so on Thus ifthe DM5812 will be using IRQ3 you should save the value ofinterruptvector 11 Before you install your ISR temporarily mask out the IRQ youwill be using This prevents the IRQ from requesting aninterruptwhile you are installing and initializing your ISR To mask the IRQ read inthe current IMR atl O port21H and set the bit that corresponds to your IRQ remember setting a bit disables interrupts on that IRQ while clearing a bit enables them The IMR is arranged so that bit 0 is for IRQO bit 1 is for IRQ1 and so on See the paragraph entitled Interrupt Mask Register IMR earlierinthis chapter for help in determiningyour IRQ s bit After setting the bit write the newvalue to I O port 21H Withthe startup IMR saved and the interrupts onyour IRQ temporarily disabled you can assign the interrupt vector to point to your ISR Again you can overwrite the appropriate entry in the vector t
19. 6 05 D4 D3 D2 D1 P57 P56 P55 P54 P53 P52 P PS0 10 Clear IRQ Program Port 4 Direction Port 5 Direction IRQ Source Registers Read Write Areadclears the IRQ status flag or provides the contents of one of three control registers Port4 Direction Port 5 Direction or Port 4 5 EPLD IRQ Source Awrite clears the digital chip or programs one ofthe three control registers depending onthe settingofbitsO and 11 Whenbits 1 and0atBA 11 are00 the read write operations clear the digital IRQ status flag read and the digital chip write When these bits are setto any other value one ofthe three Port 4 5 digital I O registers is addressed Port 4 Direction Register BA 11 bits 1 and 0 01 or all bits lt gt Droe os oa ps 02 01 bo output 4 7 4 6 PAO P44 PAS P4 2 P4 1 P4 0 This register programs the direction input or output ofeach bitat Port 4 Port 5 Direction Register BA 11 bits 1and 0 10 For all bits input 07 06 05 04 03 02 01 00 P5 7 P5 6 P5 5 P5 4 P5 3 5 2 5 1 output F50 This register programs the direction input or output ofeach bitat Port 5 Port4 5 IRQ Source Register BA 11 bits 1 40 11 27 D6 05 D4 D3 02 Di Thisregister programs the bitto be used to generate a digital interruptforthe Port 4 5 EPLD A digitalinterruptis generated when the selected bit goes from lowto high interrupt generat
20. DM6810 DM5810 User s Manual 777 RTD Embedded Technologies Inc Real Time Devices Accessing the Analog World amp BDM 610010012 Rev A DM6810 DM5810 User s Manual R RTD Embedded Technologies INC 103 Innovation Blvd State College PA 16803 0906 1 814 234 8087 1 814 234 5218 E mail sales rtd com techsupport rtd com web site http www rtd com Revision History Rev A New manual naming method Published by RTD Embedded Technologies Inc 103 Innovation Blvd State College PA 16803 0906 Copyright 1999 2002 2003 by RTD Embedded Technologies Inc rights reserved Printed in U S A The RTD Logo is a registered trademark of RTD Embedded Technologies cpuModule and utilityModule are trademarks of RTD Embedded Technologies PhoenixPICO and PheonixPICO BIOS are trademarks of Phoenix Technologies Ltd PS 2 PC XT PC AT and IBM are trademarks of International Business Machines Inc MS DOS Windows Windows 95 Windows 98 and Windows NT are trademarks of Microsoft Corp PC 104 is a registered trademark of PC 104 Consortium other trademarks appearing in this document are the property of their respective owners TableofContents INTRODUCTION p Digital 1 O 3 8254 Timer Counters n Wh
21. For all bits set as outputs a readreads the lastvalue sent out on the line and a write writes the currentloaded value outto theline Notethatwhen anyreset ofthe digital circuitryis performed clear chip or computer reset all digital lines are resetto inputs andtheir corresponding outputregisters arecleared 07 06 05 04 03 D2 Di P1 17 PIB PIS PIB PI2 P PIO 2 Clear IRQ Program Port 0 Direction Port 1 Direction IRQ Source Registers Read Write Areadclears the IRQ status flag or provides the contents of one of three control registers Port 0 Direction Port 1 Direction or Port 0 1 EPLD IRQ Source Awrite clears the digital chip or programs one ofthe three control registers depending onthe setting ofbitsOand1atBA 3 Whenbits 1 and0atBA are 00 the read write operations clear the digital IRQ status flag read and the digital chip write When these bits are setto any other value one ofthe three Port 0 1 digital I O registers is addressed Port 0 Direction Register BA 3 bits 1 and0 01 For all bits lt gt ps ba ps p2 01 po output PO 7 PO 6 POS PO 4 POS 2 PO O This register programs the direction input or output ofeachbitatPort0 Port 1 Direction Register BA 3 bits 1 and0 10 For all bits lt lt Dr pe ps pa Ds pa 01 po Plu P1 6 Pia P1 4 ES 12 1 1 10 1 output This register programs the direction input or output ofeach bit at Port 1
22. ITNESS FOR A PARTICULAR PURPOSE ARE LIMITED TO THE DURATION OF THIS WARRANTY IN THE EVENT THE PRODUCT IS NOT FREE FROM DEFECTS AS WARRANTED ABOVE THE PURCHASER S SOLE REMEDY SHALL BE REPAIR OR REPLACEMENT AS PROVID ED ABOVE UNDER NO CIRCUMSTANCES WILL RTD Embedded Technologies BE LIABLE TO THE PURCHASER OR ANY USER FOR ANY DAMAGES INCLUDING ANY INCIDENTAL OR CONSEQUENTIAL DAMAGES EXPENSES LOST PROFITS LOST SAVINGS OR OTHER DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PRODUCT SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF INCIDENTAL OR CONSEQUENTIAL DAMAGES FOR CONSUMER PRODUCTS AND SOME STATES DO NOT ALLOW LIMITATIONS ON HOW LONG AN IMPLIED WARRANTY LASTS SO THE ABOVE LIMITATIONS OR EXCLUSIONS MAY NOT APPLY TO YOU THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS AND YOU MAY ALSO HAVE OTHER RIGHTS WHICH VARY FROM STATE TO STATE D 3 Embedded Technologies Inc 103 Innovation Blvd State College PA 16803 0906 USA Our website www rtd com D 4 DM6810 DM5810 User Settings Base Address decimal
23. LK 0 COUNTER CLK O 0 5V EXT GATE GATE b 0 Gn PIN 3 T C OUT O PIN 5 EXT CLK 1 COUNTER O 1 45V GATE PIN 6 EXT GATE 1 PIN 7 T T1 OUT oor PIN 9 EXT CLK 2 TIMER COUNTER 2 5 V 10 EXT GATE 2 PIN 11 T C OUT 2 hama Jd 1 Fig 5 2 Timer Counter Circuit Block Diagram 4 MAPPING This chapter provides a complete description ofthe I O map for the DM5810 general programminginformation and howto set and clearbits ina port 41 4 2 Defining the I O Map The T O map for the DM5810is shownin Table 4 1 below As shown the board occupies 20 consecutive I O portlocations To conserve theuse of I O space the structure of the I O map is such that some of the registers control what operation you are performing at other addresses The digital registers you address at BA 2 6 and 10 are selected at BA 3 7 and 11 Thisschemeiseasilyunderstood once you review the register descriptions onthe following pages The base address designated as BA can be selected using DIP switch S1 located onthe edge of the module as described in Chapter 1 Module Settings This switch be accessed withoutremoving the module from the stack The following sections describe the register contents of each addressused in the I O map Table 4 1 DM5810 I O Map Address Register Description Read Func
24. P0 4 P0 3 P0 2 P0 0 5 VOLTS G S O O O O 6606 9 0 900 eO O S IO O D 9909 S 9 6 IS 9 9 9 9 0 2 2 9 9 9 2 9 P1 5 P1 4 P1 3 P1 2 P1 1 P1 0 5 VOLTS P5 7 CO 2 P5 6 3 4 P5 5 S 6 5 4 7 8 P5 3 9 0 P5 2 11 2 P5 1 3 4 P5 0 5 6 P3 7 OO P3 6 9 60 P3 5 63 P3 4 63 62 P3 3 65 65 P3 2 67 63 P3 1 69 60 P3 0 61 63 P1 7 6964 P1 6 65 65 6769 EXT INT 1 DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND EXT INT 2 DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND DIGITAL GND PIN 1 x f VU Ju u Y YA S D PIN 50 P2 amp P3 Mating Connector Part Numbers Part Number 1 746094 0 3M B3 3425 7650 P6 Connector EXT CLK 1 2
25. P3 and P6I O Connector PinAssignments 2 4 DM5810Block Diagram 3 3 Timer CounterCircuit Block Diagram 3 4 8254 Timer Counter Circuit Block Diagram 6 3 Digital Interrupt Timing Diagram 7 3 INTRODUCTION DM5810 DM6810 opto 22 compatible digital I O dataModule turns your IBM PC compatible cpuModule or other PC 104 computer into a high performance control system The DM5810 and DM6810 are the same board except for the addition of the AT bus connector on the DM6810 This connector allows you to stack the module easily with other AT modules and also allows you access to the AT interrupts Through the rest of this manual the module will be refered to as the DM5810 Ultra compact for embedded and portable applications the module features 48 bit programmable digital I O lines Pull up pull down resistors on each bit Three 16 bit timer counters and on board 8 MHz clock Direct connection to opto 22 I O system modules Operation from single 5V supply rtdLinx universal TSR DOS driver DOS example programs with source code in BASIC
26. Pascal and C Diagnostics software The following paragraphs briefly describe the major functions of the module A detailed discussion of module functions is included in subsequent chapters Digital I O The DM5810 has 48 bit programmable buffered TTL CMOS digital I O lines which are grouped into six 8 bit ports Port 0 through Port 5 Three EPLD chips handle the digital I O circuitry with each EPLD carrying two ports or 16 bit programmable digital I O lines Bit configurable pull up or pull down resistors are provided for all 48 lines Instructions for activat ing these pull up pull down resistors are given at the end of Chapter 1 Module Settings 8254 Timer Counters An 8254 programmable interval timer provides three 16 bit 8 MHz timer counters to support a wide range of user timing and counting functions What Comes With Your Module You receive the following items in your module package DM5810 interface module with stackthrough bus header Mounting hardware rtdLinx universal TSR DOS driver Example programs in BASIC Pascal and with source code amp diagnostics software User s manual If any item is missing or damaged please call RTD Embedded Technologies Inc Customer Service Department at 814 234 8087 If you require service outside the U S contact your local distributor Module Accessories In addition to the items included in your module package RTD Embedded Technologies Inc offers a full line
27. Port 2 3 A digital interruptis generated whentheselectedbit goes from lowto high interrupt generated on the positive going edge BA 7 Read Digital I O Status Program Digital Mode Read Write Digital IRQ Status igital interrupt Aread shows you whether a digital interrupt has occurred lets you review the states of the other bits in this register Ifbit 7 is high then a digital interrupthas taken place This provides the same status information as BA 17 bit1 Digital Mode Register igital IRQ Enab Bits 0 and 1 Selectthe clear mode initiated by a read write operation at BA 6 orthe control registeryou talk toat BA 6 Port 2 Direction Port3 Direction or Port 2 3 EPLD IRQ Select Register Bit3 Enables EPLD strobe input used with P13 header Bit4 Disables enables digital interrupts The IRQ channel is determined bythe jumper setting on P4 Bit5 Setsthe clockrate atwhich the digital lines are sampled when ina digital interruptmode Available clock sources are the 8 MHz system clock and the output of the 8254 Counter 1 16 bit programmable clock When a digital input line changes state it must stay at the new state for two edges of the clock pulse 62 5 nanoseconds whenusingthe8 MHzclock before itis recognized andbefore an interrupt canbe generated This feature eliminates noise glitches that cancause a false state change on aninput line and generate anunwanted interrupt This feature
28. Q Program Port IRQ source dependent on BA direction Port 5 direction or IRQ BA 10 Direction amp IRQ Source source dependent 11 11 Read Digital IRQ Status Set Digital Control Register Read digital interrupt status word Program digital control register 11 Clear IRQ IRQ Enable Clear interrupt line P14 interrupt sharing 16 BA Base Address 4 3 BA 0 Digital I O Port 0 Read Write This porttransfers the 8 bit Port 0 bit programmable digital input output data betweenthemodule and external devices The bits are individually programmed as input or output bywriting to the Port 0 Direction Register at BA 2 Forallbitssetas inputs areadreadstheinputvalues and awrite isignored For all bits set as outputs a readreads the lastvalue sent out on the line and a write writes the currentloaded value outto theline Notethatwhen anyreset ofthe digital circuitryis performed clear chip or computer reset all digital lines are reset to inputs andtheir corresponding outputregistersarecleared D7 D6 05 Da 93 02 Di DO 07 POS PO4 2 POO 1 Digital I O Port 1 Read Write This port transfers the 8 bit Port 1 bit programmable digital input output data betweenthe module and external devices The bits are individually programmed as input or outputbywriting to the Port 1 Direction Register at BA 2 Forallbitssetas inputs areadreadstheinputvalues and awrite isignored
29. able with a direct memory write but this isabad practice Instead use either DOS function 25H set interrupt vector or ifyour compiler provides it the libraryroutine for setting an interruptvector Remember that vector 8 is for IRQO vector 9 isfor IRQ1 and soon Ifyou need to program the source ofyour interrupts do that next For example ifyou are using the program mable interval timer to generate interrupts you must program it to runin the propermode and atthe proper rate Finally clear the bitin the IMR for the IRQ you areusing This enables interrupts onthe IRQ Restoring the Startup IMR and Interrupt Vector Before exiting your program youmustrestore the interruptmask register and interrupt vectors to the state they werein when your program started To restore the IMR write the value that was saved when your program started to T O port21H Restore the interruptvector thatwas saved atstartupwith either DOS function35H get interrupt vector orusethelibraryroutine supplied withyour compiler Performing these two steps will guarantee thatthe interrupt status ofyour computer is the same after running your program as itwas before your program started running Common Interrupt Mistakes Remember that hardware interrupts are numbered 8 through 15 eventhoughthe corresponding IRQs numbered Othrough7 Two ofthe most common mistakes whenwriting an ISR are forgetting to clear the interrupt status ofthe DM5810and forgetting to i
30. ampling Digital Lines for Change of State Inthe Digital Interruptmode the digital lines are sampled ata rate set bythe 8 MHz system clock ortheclock programmed in thetimer counter depending on the setting of bit 5 inthe Control Register When bit 5 is low the MHzclockis selected andwhen itis high the timer counter outputis selected With each clock pulse the digital circuitrylooks atthe state ofthe nextbit To provide noise rejection and prevent erroneous interrupt generation because ofnoise spikes onthe digital lines a change in the state of any bit must be seen fortwo edges of a clock pulse to be recognized by the circuit Figure 7 1 shows a diagram ofthis circuit Selecting the Interrupt Channel The IRQ channel is selected by installing a jumper on header connector P4 or P16 across the desired pair of pins as described in Chapter 1 A jumper is also installed across the G pins ifyou are using the interrupt sharing feature The jumper selectable interrupt source and the digital interrupt sources are OR d together and canuse the same interruptchannel Todetermine which interruptsource has generated an interrupt you must check bits Othrough3 ofthe status word read at 17 Thenservice the interrupt that has occurred and clear the interrOupt the jumper selectable interrupt is cleared byreading BA 16 and the digital interrupts are cleared by setting bits 1 and 0 inthe corre sponding port s Control Register and performing aread att
31. are modems disk drives and mice Your DM5810 can interrupt the processor when a variety of conditions are met Byusing these interrupts you canwrite software that effectively deals with real world events Interrupt Request Lines Toallowdifferent peripheral devices to generate interrupts onthe same computer the PCbus has eight different interruptrequest IRQ lines A transition from lowto high on one ofthese lines generates an interrupt request whichis handled bythe PC s interrupt controller Theinterrupt controller checks to see ifinterrupts are to be acknowledged from that IRQ and ifanother interruptis already in progress it decides ifthe newrequest should supersede the one in progress or ifit has to wait until the one in progress is done This prioritizing allows an interrupt to be interrupted ifthe second request has a higher priority The priority level is based onthe number ofthe IRQ IRQOhas the highest priority is second highest and so on through IRQ7 which has the lowest Many of the IRQs are used bythe standard system resources IRQOis used by the system timer IRQ1 is used by the key board IRQ3 by COM2 IRQ4 by COMI and IRQ6by the disk drives Therefore itis important for you to know which IRQ lines are available in your system for use bythe module 8259 Programmable Interrupt Controller Thechipresponsible for handling interruptrequests inthe PC isthe 8259 Programmable Interrupt Controller Touse interrupts you need
32. at Comes With Your Module 0sssesoossssssonsnussonnnnssonnnnnnsennnnnsennnnnnsennnnnnennnnsnsnnnnnnssnnnenssnnnnnssnnnnnsssnnnnsnsne Module Accessories Using This Manual 000sss00sssssnnsssssnnnsssnsunsssssnnnssssnnnsssnsnnnssnsnnnnsssnnnsssssnnnnsssnnnnssnsnunnssssnnnnsssnnnnssssnnnssssnnnnnnse When You Need Help A CHAPTER 1 MODULE SETTINGS 1 Factory Configured Switch and Jumper Settings 1 3 P4 Interrupt Channel Select Factory Setting Jumper installed on G IRQ Disabled 1 4 P5 8254 Clock and Gate Source Select Factory Settings See Figure 1 4 1 6 P13 Strobe Input Enable Factory Setting Disabled 1 7 P14 Interrupt Source Select Factory Setting OT2 1 7 S1 Base Address Factory Setting 300 hex 768 decimal 1 8 P7 through P12 Pull up Pull down Resistors on Digital O Lines
33. b MODc a bDIVc b AND a b MOD OR BASIC a b MOD c a bAND c a bORc Manycompilers havefunctionsthatcanread write either 8 or 16bitsfrom to anI O port Forexample Turbo Pascal uses Port for 8 bit port operations and PortW for 16 bits Turbo uses inportb for an 8 bitread ofa port andinport for a 16 bitread Be sure to use only 8 bitoperations with the DM5810 Clearingand Setting Bits in a Port When youclear orset one or more bits in a port you must be careful thatyou do not change the status of the other bits You can preserve the status ofall bits you do not wish to change by properuse ofthe AND and OR binary operators Using AND and OR single or multiple bits can be easily cleared in one operation Notethat most registers inthe DM5810 cannot beread back therefore you must save the value inyour program To clear a single bitin a port AND the currentvalue of the port with the value b where b 255 2 Example Clear bit 5 ina port Read in the current value of the port AND itwith 223 223 255 25 and then write the resulting value to the port In BASIC this is programmed as V_SAVE V_SAVE AND 223 OUT PortAddress V 4 12 To seta single bitin a port OR the current value ofthe port with the value b where b 274 Example Setbit3ina port Read in the currentvalue ofthe port OR it with 8 8 2 and then write the resulting valueto the port In Pascal this is programmedas V Save
34. countinthe counter and a write loads the counter with a newvalue Counting begins as soon asthe countisloaded BA 13 8254Timer Counter 1 Read Write This addressisused to read write timer counter 1 A read shows the countinthe counter and a write loads the counterwith a newvalue Counting begins as soon asthe count is loaded 14 8254 Timer Counter 2 Read Write This addressisused to read write timer counter2 A read shows the countinthe counter and a write loads the counter with newvalue Counting begins as soon asthe countis loaded 15 8254 Timer Counter Control Word Write Only 07 D6 D5 D4 2 D1 DO Counter Select This address is used to write to the control register for the 8254 The control word is defined above 16 Clear Enable Read Write Aread clears the P14 jumper selectable IRQ status flag at 17 bit3 IRQ Enable Register Awrite enables P14 interrupts and selects whether the interrupt will occur onthe positive rising edge or negative falling edge of the pulse Bit 2 is used to enable and disable the interrupt sharing circuit If you are not using shared interrupts it is best to disable this feature to ensure compatibility with all CPUs 4 10 17 IRQ Status Read Only Areadshowsthestatusofthethree EPLD digitalinterruptcircuitsandthejumper selectable interrupt circuit sothatyou determine which circuit generated aninter
35. ddress 16 outportb BaseAddress inportb BaseAddress 2 outportb BaseAddress inportb BaseAddress 6 outportb BaseAddress 3 0 7 0 11 0 inportb BaseAddress 10 outportb 0x20 0x20 InPascal Procedure ISR Interrupt begin Clear jumper selectable interrupt Set Port 0 1 digital I O clear mode Clear Port 0 1 digital interrupt Set Port 2 3 digital I O clear mode Clear Port 2 3 digital interrupt Set Port 4 5 digital I O clear mode Clear Port 4 5 digital interrupt Send EOI command to 8259 Your code goes here Do not use any DOS functions Port BaseAddress 1 Port BaseAddress 3 Port BaseAddress Port BaseAddress 7 Port BaseAddress Port BaseAddress 11 c Port BaseAddress Port 20 20 end 2 1 6 0 0 0 1 0 Clear jumper selectable interrubt Set Port 0 1 digital I O clear mode Clear Port 0 1 digital interrupt Set Port 2 3 digital I O clear mode Clear Port 2 3 digital interrupt Set Port 4 5 digital I O clear mode Clear Port 4 5 digital interrupt Send EOI command to 8259 7 6 Savingthe Startup Interrupt Mask Register IMR and Interrupt Vector Thenext step after writing the ISRis to save the startup stateoftheinterruptmask register and the interrupt vector that
36. ear chip or computer reset all digital lines are resetto inputs andtheir corresponding outputregisters arecleared 07 D6 D5 Da 93 D2 P3 6 P3 5 P34 P33 Pend PS2 P3 1 P3 0 6 Clear IRQ Program Port 2 Direction Port 3 Direction IRQ Source Registers Read Write Areadclears the IRQ status flag or providesthecontentsofone of three control registers Port 2 Direction Port 3 Direction or Port 2 3 EPLD IRQ Source Awrite clears the digital chip or programs one ofthethree control registers depending onthe setting ofbits0and1atBA 7 Whenbits 1 and0atBA 7 are 00 the read write operations clear the digital IRQ status flag read and the digital chip write When these bits are setto any other value one ofthe three Port 2 3 digital I O registers is addressed Port 2 Direction Register BA 7 bits 1 and0 01 For all bits lt gt 5 4 2 7 2 6 2 5 P2 4 P2 5 P2 2 P2 1 P2 0 output This register programs the direction input or output ofeach bit at Port 2 Port 3 Direction Register BA 7 bits 1 and0 10 For all bits lt gt va 03 52 01 po P3 7 P3 6 P35 P3 4 P3 53 P3 2 P3 1 P3 0 1 output This register programs the direction input or output ofeach bit at Port 3 Port 2 3 IRQ Source Register 7 bits 1 and 0 11 D7 D6 05 D4 93 02 Di DO Thisregister programs the bit to be used to generate a digitalinterruptforthe
37. ect Factory Setting OT2 This header connector shown in Figure 1 7 letsyou select one offour interrupt sources for interrupt genera tion These sources part ofthe EPLD digital interrupt circuitry The four sources are external inter rupt 1 P2 2 ED external interrupt 2 P3 2 the output oftimer counter 1 and OT2 the output oftimer counter 2 To connect aninterrupt source place the jumper across the desired set of pins P14 Ue A DT s PEN n ig 1 7 Interrupt Source Select Jumper P14 1 7 S1 Base Address Factory Setting 300 hex 768 decimal One of the most common causes of failurewhen you are first trying your moduleis address contention Some of your computer s I O space is already occupied by internal I O and other peripherals When the module attempts to use I O address locations already used by another device contention results and the board does notwork To avoid this problem the DM5810 has an easily accessible DIP switch S1 which lets you select any one of 16 starting addressesinthe computer s I O Should the factory setting of 300 hex 768 decimal beunsuitable for your system you can selecta different base address simply by setting the switches to any one of the values listed in Table 1 2 The table shows the switch settings and their corresponding decimal and hexadecimal in parentheses values Make sure that you verify the order of the switch numbers on the switch 1 t
38. edonthepositive goingedge BA 11 Read Digital VO Status Program Digital Mode Read Write Aread shows you whether a digital interrupt has occurred and lets you reviewthe states ofthe other bits inthis register Ifbit 7 is high then a digital interrupthas taken place This provides the same status information as 17 bit2 Digital Register Bits 0 and 1 Selectthe clear mode initiated bya read write operation at BA 10 orthe control registeryou talkto atBA 10 Port 4 Direction Port 5 Direction or Port4 5 EPLD IRQ Select Register Bit3 Enables EPLD strobe input used with P13 header Bit4 Disables enables digital interrupts The IRQ channel is determined bythejumpersettingonP4 Bit5 Setsthe clockrate atwhich the digital lines are sampled when ina digital interruptmode Available clock sources are the 8 MHz system clock and the output of the 8254 Counter 1 16 bitprogrammable clock When a digital input line changes state it must stay at the new state for two edges of the clock pulse 62 5 nanoseconds whenusingthe8 MHzclock before itis recognized andbefore an interrupt canbe generated This feature eliminates noise glitches that cancausea false state change on aninput line and generate anunwantedinterrupt This featureis detailedin Chapter 5 Bit6 Reserved Bit7 Readonly digital IRQ status 12 8254 Timer Counter 0 Read Write This address is used to read write timer counter0 A read shows the
39. ground for source to an interrupt channel pulls tri state buffers buffer interrupt channels to ground G for multiple interrupt applications disabled CLKO OSC CLK1 Sets the clock and gate sources for the 8254 CLK2 OT1 GT2 EG2 timer counter timer counters cascaded Activates pull up pull down resistors on Port 0 All bits pulled up jumpers digital I O lines installed between COM amp V Activates pull up pull down resistors on Port 1 All bits pulled up jumpers digital I O lines installed between COM amp V Activates pull up pull down resistors on Port 2 All bits pulled up jumpers digital I O lines installed between COM amp V P4 5 Activates pull up pull down resistors on Port 4 All bits pulled up jumpers digital I O lines installed between COM amp V Activates pull up pull down resistors on Port 5 All bits pulled up jumpers digital I O lines installed between COM amp V Enables and connects a strobe input to Port 0 Port 2 and or Port 4 through the EXT INT line DIS disabled Selects one of four interrupt sources for interrupt generation Connects interrupt source jumpered on P14 to an Em AT interrupt channel DM6810 only no jumper Sets the base address 300 hex 768 decimal Activates pull up pull down resistors on Port 3 All bits pulled up jumpers P10 digital I O lines installed between COM amp V 13 O O OB
40. he Port Direction IRQ Source Register address CLOCK DIGITAL INPUT IRQ OUT 7 1 Digital Interrupt Timing Diagram Interrupt Sharing This module is capable of sharing interrupts with multiple modules This circuit is described in chapter 1 If you arenotplanning onusing shared interrupts or you are not surethatyour CPU can support shared interrupts you should disable this sharing circuit by setting bit 2 at 16toa 1 By doing this the board works in normal interruptmodeandis compatible with all CPUs 7 3 Basic Programming For Interrupt Handling What Is an Interrupt Aninterruptis aneventthat causes the processorinyourcomputerto temporarily haltits current process and executeanotherroutine Uponcompletionofthe newroutine controlisreturnedto the original routine atthe point whereitsexecutionwasinterrupted Interrupts arevery handy for dealing with asynchronous events events thatoccur atless than regular intervals Keyboard activity is a good example your computer cannot predict when you might press a key and it would be a waste of processor time for it to do nothing while waiting for a keystroke to occur Thus theinterrupt schemeis used andthe processor proceeds with other tasks Then when a keystroke does occur the keyboard interrupts the processor and the processor gets the keyboard data places itin memory and then returns to what itwas doing before itwas interrupted Other common devices thatuse interrupts
41. his table is referred to as the interruptvectortable and eachentryis called an interrupt vector the new CS and IP areloaded from the interruptvector table the processor begins executing the codelocated at CS IP When the interrupt routine is completed the CS IP and flags that were pushed onthe stack when the interrupt occurred are now popped from the stack and executionresumes from the point where itwas interrupted Using Interrupts in Your Programs Adding interrupts to your software is not as difficult as itmayseem and what theyadd interms of performance is often worth the effort Note however that although it is not that hard touse interrupts the smallest mistake will oftenleadto a system hang thatrequiresa reboot This can be both frustrating and time consuming But after a few tries you ll get the bugs worked out and enjoy the benefits of properly executed interrupts In addition to reading the following paragraphs study the INTRPTS source codeincluded on your DM5810 program disk for a better under standing ofinterruptprogram development Writing an Interrupt Service Routine ISR The first step in adding interrupts to your software is to write the interrupt service routine ISR Thisis the routine thatwill automatically be executed each time aninterruptrequest occurs onthe specified IRQ An ISR is different than standard routines thatyou write First on entrance the processor registers should be pushed onto the stack BEFORE
42. hrough 4 before setting them When the switches are pulled forward they are OPEN or set to logic 1 as labeled onthe DIP switch package Whenyou set thebase address for your module record thevalue in the table inside the back cover Figure 1 8 showsthe DIP switch set for a base address of 300 hex 768 decimal Table 1 2 Base Address Switch Settings 1 Base Address Switch Setting Base Address Decimal Hex 432 1 Decimal Hex 432 1 672 CAD 1101 736 QE 0 closed 1 open 1 8 P7 through P12 Pull up Pull down Resistors on Digital I O Lines The DM5810has48 TTL CMOS compatible digital I O lines which can be interfaced with external devices These lines are divided into six ports Port 0 through Port 5 with eight bit programmable lines per port You can connect pull up or pull down resistors to any or all of these lines on a bit by bit basis You may wantto pull lines up for connection to switches This will pull the line high when the switch is disconnected Or you maywantto pull lines down forconnection to relays which control turning motors on and off These motors turnon when the digital lines controllingthem are high By pulling these lines down you can ensure that when the data acquisition system is firstturned on the motors will not switch on before the portis initialized Pull up pull down resistors have been factory installed onthe module and jumpers have been installed in the pull up position on P7 through P12 for
43. ichis the on board 8 MHz clock and EC1 whichisan external clock sourceconnected through I O connector P6 pin 5 Counter 2 hasthree clock sources OTI which cascades itto Counter 1 OSC which is the on board 8 MHzclock and EC2 whichis anexternal clock source connected through I O connector P6 pin 9 The gate of Counter 2 canbe connected to the output of Counter 1 OT1 orto an external gate source EG2 connected through I O connector P6 pin 10 Whenno external gate source is connected this line is tied high PIN 10 b EXT GATE 2 GATE OUT PIN 11 b T C OUT 2 AA ee J ON BOARD CONNECTOR XTAL 8 MHz COUNTER PIN 1 EXT CLK 0 0 5 V 2 EXT GATE 0 PIN 3 OUT O 5 V PIN 6 EXT GATE 1 7 OUT b T C OUT 1 PIN EXT CLK 2 TIMER i COUNTER CLK l 2 5 V Fig 1 5 8254 Circuit Diaaram 1 6 P13 Strobe Input Enable Factory Setting Disabled This header connector shown in Figure 1 6 connects an external signal through P2 2 EXTINT1 tothestrobe input ofthe Port 0 1 EPLD Port 2 3 P2 EPLD and or Port 4 5 P4 EPLD To enable the strobeinput on the digital I O chip ofa selected EPLD you mustremove the jumper from the DIS disable pins and place it across the desired pins Notethatmorethan one canbe strobed from the same signal P14 Interrupt Source Sel
44. ng mode where the pins labeled Gconnect a 1 kilohm pull down resistor to the output ofa high impedance tri state driver which carries the interruptrequest signal This pull down resistor drives the interruptrequestlinelowwhenever interrupts arenotactive Whenever an interrupt request is made the tri state buffer is enabled forcing the output high and generating an interrupt There are four IRQ circuits one forthe P14 jumper selectableinterrupts and one each for the digital interrupts available at Ports 0 2 and4 Their outputs are tied together through an gate allowing all interrupt sources to share the same IRQ channel To determine which circuit has generated aninterrupt onthe selected IRQ channel read the status byte WO address location BA 17 andcheck the status ofbits 0 through 3 as described Chapter 4 After the interrupthas been serviced you mustreturn the IRQ line low disabling the tri state buffer and pulling the output lowagain This is done by clearing the IRQ for the source which generated the interrupt You also have two or more modules that share the same IRQ channel You cantell which module issued the interrupt request by monitoring each module s IRQ status bit s Ifyou are not planning on sharing interrupts orifyou are not sure thatyour CPU supports interrupt sharing itis bestto disable this feature and use the interrupts in thenormal mode This will insure compatibility with all CPUs See chapter 4 for details on
45. of software and hardware accessories Call your local distributor or our main office for more information about these accessories and for help in choosing the best items to support your module s application Hardware accessories for the DM5810 include the DOP series opto 22 optoisolated digital input boards the DMR series opto 22 mechanical relay output boards the TB50 terminal board and XB50 prototype terminal board for easy signal access and prototype development the DM14 extender board for testing your module in a conventional desktop computer and XT50 twisted pair wire flat ribbon cable assembly for external interfacing Using This Manual This manual is intended to help you install your new module and get it running quickly while also providing enough detail about the module and its functions so that you can enjoy maximum use of its features even in the most complex applications We assume that you already have an understanding of data acquisition principles and that you can customize the example software or write your own applica tion programs When You Need Help This manual and the example programs in the software package included with your module provide enough information to properly use all of the module s features If you have any problems installing or using this dataModule contact our Technical Support Department 814 234 8087 during regular business hours eastern standard time or eastern daylight time or send a FAX
46. ofthe cable is connected to pin 1 ofthe connector pin 1 is marked onthe module with a small square Fortwisted pair cables pin 1 is the dark brown wire for standard single wire cables pin 1 isthe red wire 7 Makesure all connections are secure External I O Connections Figure 2 1 shows I O connector pinouts for P2 P3 and P6 Refer to these diagrams as you make your I O connections 23 P4 7 1 2 EXT INT 1 P5 7 1 2 EXT INT 2 EXT o 1 2 ext GATE o P4 6 3 4 DIGITAL GND P5 6 4 DIGITAL GND our 5 4 GND P4 5 5 6 DIGITAL GND P5 5 5 6 DIGITAL GND ExT 1 6 6 EXT GATE 1 P4 4 7 8 DIGITAL GND P5 4 7 8 DIGITAL GND our 1 2 GND P4 3 9769 DIGITAL GND P5 3 9 0 DIGITAL GND EXT CLK 2 9 ExT GATE 2 P4 2 002 DIGITAL GND P5 2 11 2 DIGITAL GND our 2 962 GND 363 DIGITAL GND P5 1 362 DIGITAL GND P4 0 99 DIGITAL GND P5 0 56 DIGITAL GND P2 7 749 DIGITAL GND P3 7 748 DIGITAL GND M P2 6 DIGITAL GND P3 6 DIGITAL GND 12 pin connector P2 5 61 62 DIGITAL GND P3 5 61 62 DIGITAL GND P2 4 63 62 DIGITAL GND P3 4 63 64 DIGITAL GND P2 3 65 66 DIGITAL GND P3 3 65 66 DIGITAL GND P2 2 62 68 DIGITAL GND P3 2 67 69 DIGITAL GND P2 1 DIGITAL GND P3 1 DIGITAL GND P2 0 61 62
47. pin2 androute them to an IRQ channel through on board header connectors P14 and PA Interrupt generationis enabled through software When interrupts are enabled arising or falling edge on EXT INT line will cause the selected IRQ line to go high depending onthe setting of BA 16 bit 1 and the IRQ status bit will change from 0 to 1 The pulse applied to the EXT INT pin should have duration of atleast 100nanoseconds Running the 5810DIAG Diagnostics Program Nowthatyourmoduleis readyto use you will want to try it out An easy to use menu driven diagnostics program 5810DIAG is included with your example software to help youverify your module s operation Youcan alsouse this program to make sure thatyour currentbase address setting does not contend with another device HARDWARE DESCRIPTION Thischapterdescribes the features of the DM5810 hardware Themajor circuits are the digital I O lines and thetimer counters 31 3 2 The DM5810hastwo major circuits the digital I O lines andthetimer counters Figure3 1showsthe block diagram ofthe module This chapter describes the hardware which makes up the major circuits ADDRESS DECODE BE CONTROL 3 X 8 BIT BIT PROGRAMMABLE DIGITAL 1 0 1 0 CONNECTOR BUS 3 X 8 BIT BIT PROGRAMMABLE DIGITAL I O e 2 2 u EI m lt lt t E n E m 5 VOLTS BIT PROGRAMMABLE CONNECTOR CONTROL
48. requesting assistance to 814 234 5218 When sending a FAX request please include your company s name and address your name your telephone number and a brief description of the problem You can also contact us through our E mail address techsupport rtd com 1 MODULESETTINGS TheDM5810hasjumperand switch settings you canchangeif necessaryforyourapplication The moduleis factory configured aslistedinthetable and shown on the layout diagram in the begin ningof this chapter Should youneedto change these settings use these easy to followinstructions before you stack the modulewith your computer system Alsonotethatby setting the jumpers as desired on header connectors P7 through P12 youcanconfigure each digital I O line tobe pulled up or pulled down This procedure is explained at the endofthis chapter 1 1 12 Factory Configured Switch and Jumper Settings Table 1 1 lists the factory settings of the user configurable jumpers and switch 0 5810 module Figure 1 1showsthemodulelayout andthe locations ofthe factory set jumpers The following paragraphs explain howto change the factory settings Pay special attention to the setting of S1 the base address switch to avoid address contention when you firstuse your moduleinyour system Table 1 1 Factory Settings Switch Factory Settings Jumper Function Controlled Jumpers Installed Connects a P14 jumper selectable or digital interrupt Jumper installed on G
49. rom defects in materials and workmanship for one year following the date of shipment from RTD Embedded Technologies INC This warranty is limited to the original purchaser of product and is not transferable During the one year warranty period RTD Embedded Technologies will repair or replace at its option any defective products or parts at no additional charge provided that the product is returned shipping prepaid to RTD Embedded Technologies replaced parts and products become the property of RTD Embedded Technologies Before returning any product for repair customers are required to contact the factory for an RMA number THIS LIMITED WARRANTY DOES NOT EXTEND TO ANY PRODUCTS WHICH HAVE BEEN DAMAGED AS A RESULT OF ACCIDENT MISUSE ABUSE such as use of incorrect input voltages improper or insufficient ventilation failure to follow the operating instructions that are provided by Embedded Technologies acts of God or other contingencies beyond the control of RTD Embedded Technologies OR AS A RESULT OF SERVICE OR MODIFICA TION BY ANYONE OTHER THAN RTD Embedded Technologies EXCEPT AS EXPRESSLY SET FORTH ABOVE NO OTHER WARRANTIES ARE EXPRESSED OR IMPLIED INCLUD ING BUT NOT LIMITED TO ANY IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE AND RTD Embedded Technologies EXPRESSLY DISCLAIMS ALL WARRANTIES NOT STATED HEREIN ALL IMPLIED WARRANTIES INCLUDING IMPLIED WARRANTIES FOR MECHANTABILITY AND F
50. rupt P14 IRQ Status no 1 IRQ Port 4 5 2 Statu Port 2 3 O no IRQ IRQ Status O 2 no 1 18 Reserved 19 Reserved 4 11 Programmingthe DM5810 This section gives you some general information about programming and the DM5810 Themoduleis programmed byreading from and writing to the correct I O portlocations These I O ports were defined inthe previous section Most high level languages suchas BASIC Pascal C and C and ofcourse assembly language make itvery easy to read write these ports The table below shows you howto read from and writeto I O ports using some popular programming languages BASIC Data INP Address OUT Address Data Data inportb Address outportb Address Data Turbo Pascal Data Port Address Port Address Data mov dx Address mov dx Address Assembly in al dx mov al Data out dx al Inadditionto being able to read write the I O ports on the DM5810 you mustbe able to perform a variety of operations that you might notnormallyuse in your programming Thetablebelow shows you some ofthe operators discussedinthis section with an example ofhoweachis used with C Pascal and BASIC Note thatthe modulus operator is used to retrieve the least significant byte LSB ofa two byte word and the integer division operatoris used toretrieve the most significant byte MSB C 96 amp a b c a b c a b amp c a b c MOD DIV AND OR a
51. rupt canbe generated This feature eliminates noise glitches that cancause a false state change on aninput line and generate anunwanted interrupt This feature is detailedin Chapter 5 Bit6 Reserved Bit7 Readonly digital IRQ status 4 Digital I O Port 2 Read Write This porttransfers the 8 bitPort2 bit programmable digital input output data betweenthemodule and external devices The bits are individually programmed aasinputor outputbywritingto the Port2 Direction Register at BA 6 Forall bitssetasinputs areadreadstheinputvalues and awriteisignored For all bits set as outputs readreadsthelastvalue sentoutonthelineand a write writes the currentloaded value outto theline Notethatwhen anyresetofthe digital circuitryis performed clear chip or computer reset all digital lines are resettoinputsandtheircorrespondingoutputregistersarecleared D7 06 D5 04 03 02 D1 DO 7 P26 P25 P24 P23 P22 P2 P20 BA 5 Digital I O Port3 Read Write This port transfers the 8 bit Port3 bit programmable digital input output data betweenthe module and external devices The bits are individually programmed as input or outputbywriting to the Port3 Direction Register at BA 6 Forallbitssetas inputs areadreadstheinputvalues and awrite isignored For all bits set as outputs a readreads the lastvalue sent out onthe line and a write writes the currentloaded value outto theline Notethatwhen anyreset ofthe digital circuitryis performed cl
52. s DOS function cannotcall itself Intypical programming this will not happen because of the way DOS iswritten But what about whenusing interrupts Then you could have a situation suchas this in your program If DOS function X isbeing executed when aninterrupt occurs and the interruptroutine makes a callto DOS function X then function Xisessentially being calledwhileitis already active Such areentrancy attempt spells disaster because DOS functions are notwritten to supportit This isa complex concept and you do notneed to understand it Just make sure thatyou donotcall any DOS functions from within your ISR The one wrinkleis that unfortunately itis not obviouswhich libraryroutines included withyour compileruse DOS functions A ruleofthumb is thatroutines which write to the screen or check the status ofor read the keyboard and any disk I O routines use DOS and should beavoidedin your ISR The same problem ofreentrancy exists for many floating point emulators as well meaning you may have to avoid floating point real math inyour ISR 7 5 Notethatthe problem ofreentrancy exists no matter what programming language you areusing Evenifyou arewritingyourISR inassemblylanguage DOS and many floating point emulators arenotreentrant Ofcourse there areways around this problem such as thosewhich involvechecking to see DOS functions are currently activewhenyourISRiscalled but such solutions are well beyond the scope ofthis discussion
53. s Read Write 4 8 BA 11 Read Digital I O Status Program Digital Mode Read Write 4 9 12 8254 Timer Counter 0 Read Write 4 10 13 8254 Timer Counter 1 Read Write 4 10 14 8254 Timer Counter2 Read Write 4 10 15 8254 Timer Counter Control Word Write Only 4 10 BA 16 Clear Enable Read Write 4 10 17 IRQ Status Read Only 4 11 BA 18 Reserved 4 11 19 Reserved 4 11 Programming the DMS8SI0_ 4 12 Clearing and Setting Bits in a Port ssoosssssnunsssssunsssssnnnnsssnnnsssnsnnnssssnnnssssnnnnssnsnnnnsssnnnnssssnnnsss
54. sedfor interrupt generation as anA D trigger orfor timing and counting functions The timers canbe programmed to operate in one of six modes depending on your application The following paragraphs briefly describeeachmode Mode 0 Event Counter Interrupt on Terminal Count This mode is typicallyused for event counting While the timer counter counts down the output is low and when the count is complete it goes high The output stays high until anew Mode O control word is written to the timer counter Mode 1 Hardware Retriggerable One Shot The outputis initially high and goes lowon the clock pulse following a trigger to begin the one shot pulse The outputremains lowuntil the count reaches 0 and then goes high andremains highuntil the clock pulse after the next trigger Mode 2 Rate Generator This mode functions like a divide by N counter and is typically used to generate a real time clock interrupt The outputis initially high and when the count decrements to 1 the output goes lowfor oneclock pulse The output then goes high again the timer counterreloads the initial count and the process is repeated This sequencecontinuesindefinitely Mode3 Square Wave Mode Similar to Mode 2 except for the duty cycle output this modeis typicallyused for baudrate generation The output is initially high and whenthe count decrements to one halfits initial count the output goes lowforthe remainder ofthe count The timer counterreloads and the outp
55. snnnnsssnnnnnsssne 4 12 CHAPTER 5 DIGITAL 5 1 Bit Programmable Digitall O eee esee toes eee sese aeos es seen ese seen ses senses seen ses eene sa 5 3 Digital Interrupts 5 3 Resetting the Digital Circuitry 5 3 Strobing Data into Ports 0 1 2 3 and 4 5 5 3 CHAPTER 6 TIMER COUNTERS 6 1 CHAPTER 7 INTERRUPTIS 7 1 P14 Jumper Selectable Interrupts 7 3 Digital Interrupts 7 3 Sampling Digital Lines for Change of State 7 3 SelectingtheInterruptChanncel 7 3 Basic Programming For Interrupt Handling 7 4 WhatlsanInterrupt
56. ssue the EOI command to the 8259 interrupt controller before exiting the ISR 7 7 7 8 APPENDIX DM6810 DM5810 SPECIFICATIONS A 1 2 DM6810 DM5810 Characteristics Typical 25 orogrammable as 12 mA 24 mA 05 82 54 MHz max or 8 MHz clock PC interrupts Iways enabled Interface Switch selectable base address 1 0 mapped Jumper selectable interrupts Digital 1 0 Number OT pesa as S E ERE EU 48 bit SOUR O oia aA aa er BE ETE E T Three 16 bit down counters 6 programmable operating modes Counter input External clock 8 on board Counter outputs Available externally used as BOUuNter SOULS Ce External gate or a Miscellaneous Inputs Outputs bus sourced 5 volts 12 volts ground Power Requirements 5V 258 mA 1 18W typical Connectors P2 and PS 50 right angle header P6 12 pin box header Hu Size Environmental tempPErT lt dentes Le dede ed onus to Storage temperature midity 3 5571 x 3 775 W x 0 6 90mm x 986mm x A 3 40 to non condensing OO 70 B5 15mm 4 B 1 APPENDIXB CONNECTOR PIN ASSIGNMENTS 2 P2 Connector 4 7 4 6 4 5 4 4 4 3 4 2 4 1 4 0 2 7 2 6 2 5 2 4 2 3 2 2 2 1 2 0 P0 7 P0 6 P0 5
57. ta canbe strobed into any or all of the three digital I O EPLDs Port 0 1 Port 2 3 and Port 4 5 by connecting the EPLD s strobe jumperon P13 and enabling the strobe by setting bit 3 high in the Control Register The strobe input is the EXT INTI signal P2 2 53 CHAPTER 6 TIMER COUNTERS Thischapterexplains the 8254 timer countercircuit onthe DM5810 6 1 6 2 An8254programmableinterval timer provides three 16 bit MHz timers for timing and counting functions suchas frequency measurement event counting and interrupts These timer counters can beconfigured in a number ofwaysto supportyour application Figure 6 1 shows a block diagram ofthetimer counter circuitry PIN 11 b T C OUT 2 ON BOARD CONNECTOR P6 XTAL 8 MHz PIN 1 EXT CLK 0 COUNTER CLK 0 m PIN 2 GATE 0 Sing PIN L T C OUT 0 5 EXT CLK 1 COUNTER O 64 EXT GATE 1 PIN 74 T C OUT 1 9 EXT CLK 2 I COUNTER PIN 10 EXT GATE 2 l Timer Counter Circuit Block Diagram Eachtimer counter has two inputs CLKin and GATE in and oneoutput timer counter OUT They can be programmed as binary or BCD downcounters bywriting the appropriate data tothe command word as described in theI Omapdiscussionin Chapter 4 Thetimer counter outputs are available at P6 where they canbeu
58. tion Decimal Digital Port 0 Read Port 0 digital input lines Program Port 0 digital output lines Digital Port 1 Read Port 1 digital input lines Program Port 1 digital output lines Clear digital IRQ status flag read Clear digital chip program Port 0 Clear IRQ Program Port Port 0 direction Port 1 direction or direction Port 1 direction or IRQ Direction amp IRQ Source IRQ source dependent on BA 3 source dependent on BA 3 2 Read Digital IRQ Status Set Digital Control Register Read digital interrupt status word Program digital control register 3 Digital Port 2 Read Port 2 digital input lines Program Port 2 digital output lines Digital VO Port Read Port 3 digital input lines Program Port 3 digital output lines Clear digital IRQ status flag read Clear digital chip program Port 2 Clear IRQ Program Port Port 2 direction Port direction or direction Port 3 direction or IRQ Direction amp IRQ Source IRQ source dependent on 7 source dependent on 7 6 Read Digital IRQ Status Set Digital Control Register Read digital interrupt status word Program digital control register BA 7 Digital Port 4 Read Port 4 digital lines Program Port 4 digital output lines Digital VO Port 5 Read Port 5 digital input lines Program Port 5 digital output lines BA 9 Clear digital IRQ status flag read Port 4 direction Port 5 direction or Clear digital chip program Port 4 Clear IR
59. to knowhowto read and set the 8259 s interrupt mask register IMR and howto send theend of interrupt EOD commandtothe 8259 Interrupt Mask Register IMR Each bit in the interrupt mask register IMR contains the mask status of an IRQ line bit Ois for IRQO bit 15 forIRQ1 andsoon Ifa bitis set equal to 1 then the corresponding IRQ is masked andit will not generate an interrupt Ifabitisclear equalto0 thenthe corresponding IRQisunmaskedand cangenerateinterrupts The IMRisprogrammedthrough port21H wo Tm 0 For all bits enabled End of Interrupt EOI Command After an interrupt service routine is complete the 8259 interrupt controller mustbenotified This is done by writing the value 20H to I O port 20H 7 4 What Exactly Happens When an Interrupt Occurs Understanding the sequence of events when aninterruptis triggered is necessaryto properly write software interrupthandlers When aninterruptrequest line is driven high bya peripheral device such asthe DM5810 the interrupt controller checks to see ifinterrupts are enabled forthat IRQ and thenchecksto seeifother interrupts are active orrequested and determineswhichinterrupthas priority The interrupt controller then interrupts the proces sor The current code segment CS instruction pointer IP and flags are pushed onthe stack for storage and a new CS and IP are loaded from a table that exists inthe lowest 1024 bytes of memory T
60. ut goes high again This processrepeats indefinitely 63 Mode4 Software Triggered Strobe The output is initially high When the initial count expires the output goeslowforoneclock pulse and then goes high again Countingis triggered bywritingthe initial count Mode 5 Hardware Triggered Strobe Retriggerable The output is initially high Counting is triggered by the rising edge of the gate input When the initial counthas expired the output goes lowfor one clock pulse and thengoeshighagain Appendix C provides the 8254 data sheet 7 INTERRUPTS This chapter explains Pl4jumper selectableinterrupts digital interrupts andbasicinterruptprogrammingtechniques 7 1 7 2 TheDM5810hasfourinterruptcircuitswhichcangenerateinterruptsonanyIRQ channel2through 7 depend ingonthesettingofthejumperonP4 P14 Jumper Selectable Interrupts TheDM5810circuitryhas four jumper selectable interrupt sources which setbyinstalling a jumper across the desired pair ofpinsatP14 Tousethese interrupts an interrupt source must be jumpered on P14 an interrupt channel mustbejumpered on P4 andthe IRQ enable mustbe set high 16 bit 0 BA 16 bit 1 sets the polarity of the interrupt Digital Interrupts EachEPLD Port 0 1 Port2 3 and Port 4 5 supports digital interrupt using one of the digital I O lines asthe interruptsource The interrupt source is software programmable as described in Chapter 5 S
61. x 8 bit ports and can be independently programmed as input or output Bit Programmable Digital I O The eight Port0 Port 1 Port 2 Port3 Port 4 and Port 5 digital lines are individually set for input or output by writing to the respective port Direction Registersat BA 2 BA 6 and BA 10 The input lines are read and the output lines are written at BA 0 BA 4 and BA 7 Direction Register utput DigitalInterrupts EachEPLD chipcontains the digital I O circuitryfortwo ports or 16 bit programmablelines There are three EPLDs Port 0 1 Port 2 3 and Port 4 5 Oneline oneach chipcanbe programmed asa digital interrupt by program ming the IRQ select register with the digital line to be monitored selecting an IRQ channel on P4 and setting the IRQenable bit high inthe Control Register If for example you wanted to use Port 0 bit 6 to generate aninterrupt you would select the desired IRQ channelonP4andsetbits4 1 and0atBA 3hightoaccessthe IRQ Source Register and enable digital interrupts Then you would write 0110 inthe bottom four bits at BA 2 to select digital I O line P0 6 Every time P0 6 goes from lowto high a positive going edge an interrupt is generated Resetting the Digital Circuitry Whena digital chip clear is issued all of the digital I O lines are setupas inputs and theircorresponding output registers arecleared Strobing Data into Ports 0 1 2 3 and 4 5 External da
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