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DM5414/DM6414 12-bit DAS

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1. CHAPTER 4 BOARD OPERATION AND PROGRAMMING This chapter explains the I O map of the DM5414 in detail and shows how to program the onboard peripherals such as the LM12458 DAS chips the 8254 Timer and the Digital I O DM5414 DM6414 RTD Finland Oy 1998 2001 Page 40 Defining the I O Map The I O map of the DM5414 is shown in Tables 4 1 and 4 2 As shown the board occupies 48 consecutive I O addresses To conserve the use of I O space the structure of the I O map is such that some of the registers control what peripherals are accessed in other addresses The control registers at addresses BA 20 and BA 21 select the active DAS or D A chips and select either the 8254 timer of the Advanced Bit Programmable Digital I O chip These functions can easily be understood by reviewing the following pages The Base Address designated as BA can be selected by the two base address jumpers as described in Chapter 1 Module Settings These jumpers can be changed without removing the module from the PC 104 stack The following sections describe the register contents of each address used in the I O map Table 4 2 shows the I O address locations for each DAS chip The active DAS chip is selected with the DAS selection register located in address BA 20 DM5414 DM6414 RTD Finland Oy 1998 2001 Page 41 Table4 1 DM5414 1 0 Map Other Peripherals Address Description
2. DM5414 DM6414 12 bit DAS module User s Manual Real Time Devices Finland Oy Hardware Release 2 0 Real Time Devices Finland Oy Lepolantie 14 FIN 00660 Helsinki Finland Tel 358 9 346 4538 Fax 358 9 346 4539 Email sales rtdfinland fi URL www rtdfinland fi DM5414 DM6414 RTD Finland Oy 1998 2001 ISO9001 and AS9100 Certified Page 1 IMPORTANT Although this information contained in this manual has been carefully verified RTD Finland Oy assumes no responsibility for errors that may appear in this manual or for any damage to things or persons resulting from improper use of this manual or of the related software RTD Finland Oy reserves the right to change the contents and for of this manual as well as the features and specifications of this product at any time without notice Published by Real Time Devices Finland Oy Lepolantie 14 FIN 00660 Helsinki Finland Copyright O 1995 2001 by RTD Finland Oy All rights reserved Printed in Finland DM5414 DM6414 RTD Finland Oy 1998 2001 Page 2 Table of Contents INTRODUCTION Analog to Digital conversion Digital to Analog conversion 8254 Timer Counter Digital VO Mechanical description Connector description What comes with your board Board accessories Application software and drivers Hardware accessories Using this manual When you need help CHAPTER 1 BOARD SETTINGS Factory Configured Jumper Settings Base Address Jumpers 8254
3. 100 Mode4 software triggered strobe 101 Mode5S hw triggered strobe RTD Finland Oy 1998 2001 Page 46 Overlay Bit 1 BA 24 Digital VO Port 0 Write Read or 06 05 pe 03 02 01 00 P0 7 P0 6 POS PO4 P0 3 PO 2 PO 1 P0 0 This port transfers the 8 bit port 0 bit programmable digital I O data between the board and external devices The bits are individually programmable as inputs or outputs by writing to the Direction Control Register at BA 26 For all bits set as inputs a read reads the input values and a write operation is ignored For all the bits set as outputs a read will return the last value written to the outputs and a write sends the value out Note After a board reset all lines are set to inputs and their corresponding output registers are cleared BA 25 Digital VO Port 1 Write Read or ne vs pe 03 02 01 00 VYO7 VO 6 VOS 104 YO3 10 2 VO1 VO O This port transfers the 8 bit port 1 bit programmable digital I O data between the board and external devices The bits are individually programmable as inputs or outputs by writing to the Direction Control Register at BA 26 For all bits set as inputs a read reads the input values and a write operation is ignored For all the bits set as outputs a read will return the last value written to the outputs and a write sends the value out Note After a board reset all lines are set to be inputs and their corresponding output registers are cleared DM5414
4. are ignored when making the match Note Make sure that bit 3 in BA 27 is set to 1 selecting match mode BEFORE writing to the Compare Register value at this address In the event mode where an interrupt is generated when any port O bit changes its current state the value which caused the interrupt is latched at this register and can be read from it Bits can also be selectively masked using the Mask Register so a change of state is ignored on these lines in the event mode Read Digital IRQ Status Program Digital Mode BA 27 Write Read A read shows you whether a digital interrupt has occurred bit 6 whether a strobe has occurred bit 7 and lets you review the current state of bits 0 5 Read BA 27 port 0 reg select Strobe status 0 no l yes Port 1 direction Digital IRQ status Digital IRQ mode 0 no interrupt Digital IRQ enable 1 dig interrupt De Digital sample clock select Write Reserved bits BA 27 port 0 reg select DO clear mode Digital Sample CLK Port 1 dir Ol dir register 0 8 MHz system clock 0 input 10 mask reg 1 Programmable clock 1 output 1 1 comp reg Digital IRQ enable Digital IRQ mode 0 disabled 0 event mode 1 enabled 1 match mode DM5414 DM6414 RTD Finland Oy 1998 2001 Page 49 Bits 0 and 1 Select the clear mode initiated by the read or write operation at BA 26 or the port 0 control register you talk to at BA 27 Direction Mask or Compare Register Bit 2 Sets the direct
5. A DM5414 DM6414 Specifications Host Interface VO mapped occupies 32 bytes Jumper selectable base address 4 options 8 bit data bus 16 bit PC 104 bus connector Jumper selectable interrupts XT and AT Analog Interfaces 32 analog inputs For full specification please consult component specific datasheet for the LM12458CIV A D converter 8 12 bit resolution programmable 0 to 2 5V or 0 5 0V input range Single ended or differential operation Interrupt support 4 analog outputs 12 bit resolution Simultaneously updated 4 output ranges channel by channel configurable 0 5V 0 10V 5V 10V Digital O Number of lines 16 16 16 register configured 8 inputs 8 outputs 8 bit programmable digital I O lines 8 port programmable digital I O lines with advanced modes and Interrupt support Timers Number of timers 3 8254 compatible Clock sources include 8MHz oscillator or external source Counters cascadable External gating Interrupt support DM5414 DM6414 RTD Finland Oy 1998 2001 Page 64 Connectors Analog Digital I O s Header connectors 50 Pin Host bus AT PC 104 bus Electrical Operating temperature range 0 to 70C or 40 to 85 C Supply voltage 5V only Power consuption 1 5W DM5414 DM6414 RTD Finland Oy 1998 2001
6. DM6414 RTD Finland Oy 1998 2001 Page 47 BA 26 Port 0 Direction Mask Compare Write Read CEEEPEEE xs BITS 0 1 00 Register data Don t care Performing a write to this address with BA 27 register bits 0 1 at 00 will clear the digital chip from software Performing a read will clear the interrupt status flag Direction Register CEEEEEEE BITS 0 1 P0 7 P06 POS P04 P03 P02 P01 POO 01 0 gt INPUT 1 gt OUTPUT Mask Register BITS 0 1 P0 7 P0 6 P0 5 P04 P03 PO2 PO 1 POO 10 0 gt INPUT 1 gt OUTPUT In the Advanced Interrupt modes this register is used to mask out specific bits when monitoring the bit pattern present at port O for interrupt generation In normal operation where the Advanced Interrupt feature is not being used any bit which is masked by writing 1 to that bit will not change state regardless of the data written to port 0 For example if you set the state of the bit o low and then mask this bit the state will remain low regardless of what you output at port 0 An output of 1 will not change the state of the output until the bit is unmasked DM5414 DM6414 RTD Finland Oy 1998 2001 Page 48 Compare Register BA 27 BITS 0 1 10 This register is used for the Advanced Digital Interrupt modes In the match mode where an interrupt is generated when the port 0 bits match a preloaded value this register is used to load the bit pattern to be matched at port 0 Bits can be selectively masked so that they
7. OUT4 OUT3 OUT2 OUT OUTO IN6 INN M IN3 IN2 INI MO IN7 BA 2F Board status register Read only This register returns the board general status bits This information may be used to read back the hardware interrupt output states of the DAS chips or 06 05 09 03 02 01 00 RESERVED BITS DAS3 DAS2 DASI DASO DM5414 DM6414 RTD Finland Oy 1998 2001 Page 52 LM12458 DAS Chip programming datasheet reprinted This section describes the internal programmable functions of each DAS chip Make sure you enable the correct chips for programming first by setting the DAS enable bits in address BA 20 DM5414 DM6414 RTD Finland Oy 1998 2001 Page 53 Programming the DM5414 This section gives you some general information about programming the DM5414 board and then walks you through the major programming functions of the DM5414 These descriptions will help you as you use the example programs and function libraries included with this board All of the program descriptions use decimal values unless otherwise specified The DM5414 is programmed by writing to and reading from the correct I O port addresses of the board These I O ports were described in the previous section of this chapter The following example shows how to perform a 8 bit read and write I O port addresses using C syntax and assembly code Read Write C syntax var inp address outp address data Assembly mov dx address mov dx address in ax dx mov ax dat
8. Oy 1998 2001 Page 36 Reprint of LM12458 DAS Chip datasheet DM5414 DM6414 RTD Finland Oy 1998 2001 Page 37 D A Conversion Circuitry Four 12 bit analog outputs are included on the DM5414 These four channels are grouped as follows Channels 1 and 2 are located in the primary connector Channels 3 and 4 are located in the secondary connector Each of the channel pairs can have independent range settings Each of the four channels can be set for bipolar or unipolar operation in the selected range The 10 volt ranges have a resolution of 2 44 millivolts and the 5 volt range has a resolution of 1 22 millivolts Timer Counters An 8254 programmable interval timer provides three 16 bit 8 Mhz timer counters to support a wide range of timing and counting functions Two of the timer counters TCO and TC1 are cascaded so that they can be used for the pacer clock The pacer clock is described in Chapter 4 Note that each DAS chip can use it s internal counter as a pacer clock freeing counter timers TCO and TC1 for user applications Timer TC2 is always free for the user The timers have different options for clock sources as well as gate signals Figure 3 2 shows the timer counter circuitry of the DM5414 T C OUT 1 pin42 T C OUT 2 pin44 TRIGGER IN pin39 Fig 3 2 8254 Timer Counter Circuit Block Diagram DM5414 DM6414 RTD Finland Oy 1998 2001 Page 38 Each Timer Counter has two inputs CLK in and GATE in and one output time
9. bit 1 to 1 and bit 0 to 0 Step 2 Write low byte and high byte to BA 29 and BA 30 Step 3 Load DAC storage registers to analog outputs by reading from BA 21 NOTE Writing to storage registers will not update the outputs DM5414 DM6414 RTD Finland Oy 1998 2001 Page 50 After the DAC storage registers are loaded you must perform a load to transfer the data to the outputs This is performed by reading from BA 21 The read cycle will trigger the contents of the storage registers to the analog outputs BA 2C Board setup register 1 Read only This register returns the status of the internal control bits of the register in BA 20 DAS chip selection the DM5414 Register bits DAS selected 0 DAS1 DASO DAS3 DAS2 BA 2D Board setup register 2 Read only This register returns the status of the internal control bits of the the DM5414 DAC selection bits and the overlay bit Bit 3 is the interrupt Status bit of the Advanced Digital I O chip Register bits DAC selected 0 DAC1 DACO PPI_IRQ STAT OVERLAY BA 2E Digital I O register Write Read The DM5414 features 16 general purpose digital I O in two ports One 8 bit output port and an 8 bit input port These ports are available at the secondary I O connector J4 The pinouts are described in figure 2 4 The input port has 47K pulldown resistors connected to each input line DM5414 DM6414 RTD Finland Oy 1998 2001 Page 51 D7 D5 D4 D3 D2 Di OUT7 OUT6 OUTS
10. doing this The vectors for the hardware interrupts on the XT bus are vectors 8 15 where IRQO uses vector 8 and IRQ7 uses vector 15 Thus if your DM5414 is using IRQS it corresponds to vector number 13 DM5414 DM6414 RTD Finland Oy 1998 2001 Page 58 Before you install your ISR temporarily mask out the IRQ you will be using This prevents the IRQ from requesting an interrupt while you are installing and initializing your ISR To mask the IRQ read the current IMR at I O port 21h and set the bit that corresponds to tout IRQ The IMR is arranged so that bit 0 is for IRQO and bit 7 is for IRQ7 See the paragraph entitled Interrupt Mask Register IMR earlier in this discussion for help in determining your IRQ s bit After setting the bit write the new value to I O port 21h with the startup IMR saved and the interrupts temporarily disabled you can assign the interrupt vector to point to your ISR Again you can overwrite the appropriate entry in the vector table with a direct memory write but this is not recommended Instead use the DOS function 25h Set Interrupt Vector or if your compiler provides it the library routine for setting up interrupt vectors Remember that interrupt vector 8 corresponds to IRQO vector 9 for IRQ etc If you need to program the source of your interrupts do that next For example if you are using transmitted or received messages as an interrupt source program it to do that Finally clear the mask bit fo
11. input channel of the channel group you are using see above and connect the low side of the signal to another analog input channel of the channel group you are using Then for signal sources with a separate ground reference connect the ground from the signal source to one of the analog ground pins on the expansion connector you are using SINGLE ENDED INPUT al INPUT SIGNAL pag ALS Li mua 134 3 RL Lai z4seciu Hg 135 fis ino 145 a Rees 1 2 00 Ha Pag De IHS abs ing Lae Tue In Ges in eat sync 22 Led Ro Syd He ALE 5 PCLk ab 58 1 Figure 2 6 shows how these connections are made DM5414 DM6414 RTD Finland Oy 1998 2001 Page 32 DIFFERENTIAL JNFUT INPUT SI GMAIL Wl 11129458011 TN Jr cfr e ale ale rr ar PRO bh a irdi sem De e PAI ee e PID ah L ODD POD ar e e So T a T a Ta T a ar Fig 2 7 Differential Input Connection DM5414 DM6414 RTD Finland Oy 1998 2001 Page 33 Connecting the Analog Outputs For each of the four analog outputs connect the high side of the device receiving the output to the AOUT channel J3 17 J3 19 J4 17 J4 19 and connect the low side of the device to an ANALOG GROUND J3 18 J3 20 J4 18 J4 20 Connecting the Timer Counters and Digital I O For all these connections the high side of the signals are connected to the appropriate signal pin on either the primary I O connector J3 or the Secondary I O connector J4 The l
12. of Cmp intr sign of low limit 15 BA 0 RAM Pointer 10 Cmp high limit Comparison high limit 0 BA 1 Polarity of Cmp intr sign of high limit 0 BA E i Comparison high limit 15 BA F n Polarity of Cmp intr sign of high limit 15 BA 10 Read Write DAS Configuration Register 1 BA 11 Read Write DAS Configuration Register 2 BA 12 Read Write DAS Interrupt Enable Register 1 BA 13 Read Write DAS Interrupt Enable Register 2 BA 14 Read Write DAS Interrupt Status Register 1 BA 15 Read Write DAS Interrupt Status Register 2 BA 16 Read Write DAS Acquisition Timer Register 1 BA 17 Read Write DAS Acquisition Timer Register 2 BA 18 Read Write DAS Conversion FIFO low byte BA 19 Read Write DAS Conversion FIFO high byte BA 1A Read Write DAS low Limit Status Register BA 1B Read Write DAS high Limit Status Register Identical 1 0 addressing for each DAS chip Chip selected in cnf register BA 20 DM5414 DM6414 RTD Finland Oy 1998 2001 Page 43 DM5414 I O Map Other Peripherals BA 20 DAS chip selection register Write Register bits DAS selected 1 DAS1 DASO DAS3 DAS2 BA 21 DAC control register Write Register bits DAC Select 1 Overlay 1 gt Dig I O DAC1 DACO Overlay 0 gt Timer OVERLAY BA 21 DAC control register Read Performing a read to this address will load the D A converters with the output data written to the D A output registers DM5414 DM6414 RTD Finland Oy 1998 2001 Pag
13. to 5V and you select unipolar you have a 0 to 5V output range Figure 1 11a Bipolar operation on D A channels 3 and 4 J5 JE Figure 1 11b Unipolar operation on D A channels 3 and 4 J5 JE DM5414 DM6414 RTD Finland Oy 1998 2001 Page 24 B5 DAS1 Reference selection Factory setting 2 5V B3 DAS2 Reference selection Factory setting 2 5V B6 DAS3 Reference selection Factory setting 2 5V B1 DAS4 Reference selection Factory setting 2 5V The input range can be set individually for each DAS chip A three terminal solder jumper selects the range to be either 0 2 5V or 0 5 0V These solder jumpers are located on the solder side under side of your DM5414 They are grouped so that the range solder jumper is located approximately under each LM12458 DAS chip See figure 1 12 for detailed locations of these jumpers Fig 1 12 Location of DAS reference jumpers B1 B6 B3 B5 pmm 1 D q be pa 13 YJ CE E ta ls mm 8J DEJ eo a a 4 I DM5414 DM6414 RTD Finland Oy 1998 2001 Page 25 This page is left intentionally blank DM5414 DM6414 RTD Finland Oy 1998 2001 Page 26 CHAPTER 2 BOARD INSTALLATION The DM5414 DM6414 is easy to install in your cpuModule of other PC 104 based system This chapter tells you step by step how to connect your module into your stack After you have made all of your connections you can turn on your computer and run the diagnostic and test sof
14. 1 Description 2 BA 20 Write only DAS chip selection register BA 21 Read Write Rd gt Load DACs Wr gt DAC chip select Overlay bit BA 22 Reserved Reserved BA 23 Write Software trigger Overlay 0 BA 24 Read Write 8254 Timer Counter 0 BA 25 Read Write 8254 Timer Counter 1 BA 26 Read Write 8254 Timer Counter 2 BA 27 Write only 8254 Control byte Overlay 1 BA 24 Read Write Port 0 Data register BA 25 Read Write Port 1 Data register BA 26 Read Write Port 0 Control Byte BA 27 Write only Digital I O chip Control byte BA 28 Write only DAC 1 Register BA 29 Write only DAC 1 Register BA 2A Write only DAC 1 Register BA 2B Write only DAC 1 Register BA 2C Read only Board setup register 1 BA 2D Read only Board setup register 2 BA 2E Read Write Digital I O Connector J4 BA 2F Reserved Reserved BA Base Address Overlay bit is bit 2 in address BA 21 DM5414 DM6414 RTD Finland Oy 1998 2001 Page 42 o Table4 1 DM5414 1 0 Map DAS chips Address Description 1 Description 2 BA 0 RAM Pointer 00 Program Sequencer Instruction 0 BA 1 E Parameter field for Instruction 0 BA E j Sequencer Instruction 15 BA F i Parameter field for Instruction 15 BA 0 RAM Pointer 01 Cmp low limit Comparison low limit 0 BA 1 i Polarity of Cmp intr sign of low limit 0 BA E Comparison low limit 15 BA F Polarity
15. 14 DM6414 RTD Finland Oy 1998 2001 External I O connections Primary 50 Pin Analog Digital Expansion Connector Page 29 Figure 2 3 shows the DM5414 s J3 primary I O connector pinout Figure 2 4 shows the DM5414 s J4 secondary I O connector pinout Refer to these diagrams when you are making I O connections Note that 12V at pins 47 and 12V at pins 49 are only available if your system bus supplies these voltages These voltages are not generated by the DM5414 AIN1 AIN2 3 AIN3 ES AIN4 7 AINS i AIN6 11 AIN7 13 AINS 15 AOUTI 17 AOUT2 19 AGND 21 PA7 23 PA6 253 PAS 27 PA4 29 PA3 31 PA2 33 PAI 35 PAO 37 TRIGGER IN 39 EXT GATE 1 41 SYNC IN OUT 43 EXT CLOCK 45 12V VCC 47 12V VSS 49 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 AIN9 AIN10 AIN11 AIN12 AIN13 AIN14 AIN15 AIN16 AGND AGND AGND PC7 PC6 PC5 PC4 PC3 PC2 PC1 PCO DGND T C OUT 1 T C OUT 2 EXT GATE 2 5V DGND Fig 2 3 Primary expansion connector pinout J3 NOTE DM5414 DM6414 Digital VO ports PC 0 7 are port programmable inputs or outputs and are derived from the advanced Digital Interface Chip Port PA 0 7 is bit programmable and has Advanced Masking Modes Please refer to the more detailed discussion on the functionality of the digital I O in Chapter 3 RTD Finland Oy 1998 2001 Page 30 Secondary 50 Pin Analog Dig
16. 1998 2001 Page 22 J5 J Figure 1 9b Range jumper for D A channels 3 and 4 set for 5V range D A converter channel polarity select Channels 1 2 and 3 4 DALIP DA channel 1 Bip Unip DA2P DA channel 2 Bip Unip DA3_P DA channel 3 Bip Unip DA4P DA channel 4 Bip Unip DA1_P D A converter channel 1 Polarity selection Factory setting bipolar DA2_P D A converter channel 2 Polarity selection Factory setting bipolar The jumpers in jumper fields J7 and J8 select the polarity of the D A converter channels 1 and 2 Available selections are unipolar or bipolar For example if you have selected the range to be 10V and you set the polarity to bipolar you will achieve a 10V to 10V output range Similarly if your range is set to 5V and you select unipolar you have a 0 to 5V output range Figure 1 10a Bipolar operation on D A channels 1 and 2 JB i Figure 1 10b Unipolar operation on D A channels 1 and 2 DM5414 DM6414 RTD Finland Oy 1998 2001 Page 23 JB J7 DA3_P D A converter channel 3 Polarity selection Factory setting bipolar DA4 P D A converter channel 4 Polarity selection Factory setting bipolar The jumpers in jumper fields J5 and J6 select the polarity of the D A converter channels 3 and 4 Available selections are unipolar or bipolar For example if you have selected the range to be 10V and you set the polarity to bipolar you will achieve a 10V to 10V output range Similarly if your range is set
17. C 1 OUT pin 33 pin 42 and the timer counter 2 s output is available at T C 2 OUT J3 pin 44 where they can be used for interrupt generation DAS triggers or for other counting purposes The timer counters can be programmed to operate in one of six modes depending on your application The following section briefly describes each mode DM5414 DM6414 RTD Finland Oy 1998 2001 Page 60 I O CONNECTOR 5 EXT CLK pin4b EXT GATE 1 ph41 o T C OUT 1 pin42 T C OUT 2 pin44 TRIGGER IN pin39 EXT GATE 2 pin46 Fig 4 1 Block diagram of the timer counter unit of your DM5414 Mode 0 Event Counter This mode is typically used 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 a new mode 0 control word is written to the timer counter Mode 1 Hardware Retriggerable one shot The output is initially high and goes low on the clock pulse following a trigger to begin the one shot pulse The output remains low until the count reaches 0 and then goes high and remains high until 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 output is initially high and when the count decrements to 1 the output goes low for one clock pulse The output then goes high again the counter reloads the initial count and the pr
18. I command to acknowledge the 8259 interrupt controller Interrupt Mask Register IMR Each bit in the interrupt mask register IMR contains the mask status of the interrupt line If a bit is set equal to 1 then the corresponding IRQ is masked and it will not generate an interrupt If a bit is cleared equal to 0 then the corresponding IRQ is not masked and it can generate an interrupt The interrupt mask register is programmed through port 21h End of Interrupt EOI Command After an interrupt service routine is complete the 8259 Interrupt Controller must be acknowledged by writing the value 20h to port 20h What exactly happens when an interrupt occurs Understanding the sequence of events when an interrupt is triggered is necessary to correctly write interrupt handlers When an interrupt request line is driven high by a peripheral device such as the DM5414 the interrupt controller checks to see if interrupts are enabled for that IRQ and then checks to see if other interrupts are active or requested and determines which interrupt has priority The interrupt controller then interrupts the processor The current code segment CS instruction pointer IP and flags are pushed onto the system stack and a new set if CS and IP are loaded from the lowest 1024 bytes of memory This table is referred to as the interrupt vector table and each entry to this table is called an interrupt vector Once the new CS and IP are loaded from t
19. Timer Counter Sources Interrupt Channel select External 5V Reference Type Tracking Ratiometric Absolute D A converter range select Channels 1 2 and 3 4 D A converter channel polarity select Channels 1 2 and 3 4 Internal 2 5V External Reference selection for A D converter CHAPTER 2 BOARD INSTALLATION Board installation External I O connections Primary 50 pin Analog Digital Expansion Connector Secondary 50 pin Analog Digital Expansion Connector Connecting the analog input pins Connecting the analog outputs Connecting the Timer Counters and digital VO CHAPTER 3 HARDWARE DESCRIPTION A D conversion circuitry Reprint of LM12458 DAS Chip datasheet D A conversion circuitry Timer Counters Digital I O Advanced Bit Programmable Digital I O DM5414 DM6414 RTD Finland Oy 1998 2001 CHAPTER 4 BOARD OPERATION AND PROGRAMMING Defining the I O map Onboard Peripherals Base 20 DAS chip enable Base 21 Base 22 Reserved Base 23 Software trigger DAC chip enable Load DAC s Overlay bit 0 Base 24 Base 25 Base 26 Base 27 8254 Timer Counter 0 8254 Timer Counter 1 8254 Timer Counter 2 8254 Timer Counter Control byte Overlay bit 1 Base 24 Base 25 Base 26 Base 27 Base 28 Base 29 Base 2A Base 2B Base 2C Base 2D Base 2E Base 2F DM5414 DM6414 Port 0 Data Port 1 Data Port 0 Control byte Digital Chip Control byte DAC 1 Register DAC 2 Register DAC 3 Register DAC 4 Register Board Setup Re
20. a out dx ax 8 bit operations must be performed to the DM5414 board to ensure correct operation Clearing and setting bits in an I O port When you clear or set bits in an I O port you must be careful not to alter the status of other bits You can preserve the status of all the bits you do not wish to change by proper use of the bitwise AND and OR operators Using and or operators single or multiple bits can easily be set or cleared in one line operations 1 To clear a single bit in a port AND the current value of the port with the value B where B 255 2 exp bit 2 To set a single bit in a port OR the current value of the port with the value B where B 2 exp bit Bits are numbered from 0 7 for the low byte of a word and from 8 15 for the high byte of a word Setting and clearing of multiple bits in a bye or word is more complex 3 To clear multiple bits in a port AND the current value of the port with the value B where B 255 the sum of the values of the bits to be cleared Note that the bits do not have to be consecutive 4 To set multiple bits in a port OR the current value of the port with the value B where B sum of the individual bits to be set DM5414 DM6414 RTD Finland Oy 1998 2001 Page 54 A D conversions The A D converter chip data acquisition sequencers must first be programmed to before A D conversions can be made Conversions can not be directly started from the host program with a
21. and the interrupt routine makes a call to the DOS function X then function X is essentially being called while active Such cases will cause the computer to crash DOS does not support such operation A general rule is that do not call any functions that use the screen read keyboard input and any file I O routines should not be used in ISR s The same problem of reentrancy exists for many floating point emulators as well meaning you should avoid floating point mathematical operations in your ISR Note that the problem of reentrancy exists no matter what programming language you use Even if you are writing your ISR in Assembly language DOS and many floating point emulators are not reentrant Of course there are ways to avoid this problem such as those which involve checking if any DOS functions are currently active when your ISR is called but such solutions are beyond the scope of this manual The second major concern when writing ISR s is to make them as short as possible in term of execution time Spending long times in interrupt service routines may mean that other important interrupts are not serviced Also if you spend too long in your ISR it may be called again before you have exited This will lead to your computer hanging up and will require you to restart your computer DM5414 DM6414 RTD Finland Oy 1998 2001 Page 57 Your ISR should have the following structure Push any processor registers used in your ISR Most C com
22. directly interface to I O signals The signal definition of these connectors is compatible with the analog digital PC 104 dataModules manufactured by RTD DM5414 DM6414 RTD Finland Oy 1998 2001 Page 11 What comes with your board You receive the following items in your DM5414 package DM5414 interface module with stackthrough bus connector Software and diagnostics diskette with C source code User s manual If any item is missing or damaged please call Real Time Devices Finland Customer Service Department at 358 9 346 4538 Board accessories In addition to the items included in your DM5414 delivery several software and hardware accessories are available Call your distributor for more information on these accessories and for help in choosing the best items to support your instrumentation system Application programs and drivers Hardware accessories Real Time Devices can supply a complete set of accessories to your DM5414 DM6414 card These include IDAN enclosures power supplies signal conditioning modules terminal boards and other interconnection systems Using this manual This manual is intended to help you install your new DM5414 card and get it running quickly while also providing enough detail about the board and it s functions so that you can enjoy maximum use of it s features even in the most demanding applications We assume you already have an understanding of basic data acquisition principles Whe
23. e 44 This page is left intentionally blank DM5414 DM6414 RTD Finland Oy 1998 2001 Overlay Bit 0 BA 24 Page 45 8254 Timer Counter 0 Write Read A read to this address shows the current contents of the timer TO A write to this address reloads a new value to the timer Counting begins as soon as the timer has bee loaded This timer is cascaded with timer T1 to form the 32 bit pacer clock on the DM5414 BA 25 8254 Timer Counter 1 Write Read A read to this address shows the current contents of the timer T1 A write to this address reloads a new value to the timer Counting begins as soon as the timer has bee loaded This timer is cascaded with timer TO to form the 32 bit pacer clock on the DM5414 BA 26 8254 Timer Counter 2 Write Read A read to this address shows the current contents of the timer TO A write to this address reloads a new value to the timer Counting begins as soon as the timer has bee loaded This timer is cascaded with timer TO and T1 or used independently The output of this timer may be connected to the external trigger input of the DM5414 BA 27 COUNT SEL 00 counterO 01 counterl 10 counter2 11 readback DM5414 DM6414 8254 Control word READ LOAD 00 Latching 01 RD LD LSB only 10 RD LD MSB only 11 RD LD LSB MSB Write only BCD BIN 0 BINARY 1 BCD COUNTER MODE 000 Modeo0 event count 001 Model programmable 1 shot 010 Mode2 rate generator 011 Mode3 sq wave rate generator
24. ed to an external IRQ line The 8254 timer counter is not needed to set the acquisition speed of the DAS chips since they have internal 16 bit timer counters to do this Digital I O The DM5414 has 16 latched TTL CMOS general purpose digital I O available in the secondary expansion connector J4 These ports have 8 outputs in port C lines and 8 inputs in port A lines The input port has onboard 47K pulldown resistors These ports are not bit addressable 16 buffered TTL CMOS lines are also available grouped as eight independent bit programmable lines in Port 0 and an 8 bit programmable port at Port 1 The bit programmable lines support RTD s two Advanced Digital Interrupt modes An interrupt flag can be set when any bit changes value event interrupt or when the lines match a programmed value match interrupt For either mode masking can be used to monitor selected lines Port 0 is pulled low with 47K pulldown resistors Mechanical description The DM5414 is designed on a PC 104 form factor An easy mechanical interface to both PC 104 and EUROCARD systems can be achieved Stack your PC 104 compatible computer directly on the DM5414 using the onboard mounting holes DM5414 is XT bus DM6414 is an AT bus board version The DM6414 also can be installed in the RTD IDAN modular aluminium enclosure system either in a single or double high frame Connector description There are two 50 pin analog digital interface connectors on the DM5414 to
25. gical 0 connecting the jumper to a 1 When you set the base address of the module record the setting in the table inside the back cover of this manual after the Appendices Table 1 2 Base Address Jumper 3 4 settings Table 1 2 Base Address Jumpers Address in HEX Address in Decimal Jumpers 1A0h 416d X3 0 X4 0 280h 640d X3 1 xX4 0 300h 768d X3 0 X4 1 380h 896d X3 1 X4 1 0 Jumper removed Jumper closed Fig 1 3 Base address jumpers t PE DM5414 DM6414 RTD Finland Oy 1998 2001 Page 17 TIMERS Clock sources for Timer Counters Factory settings CLK0 OSC CLK1 OT0 CLK2 OT2 The jumpers shown in figure 1 4 let you select the clock sources for the 8254 based timer counters TCO TC1 and TC2 The factory setting cascades all the three counter timers with the clock source for TCO being the onboard 8 MHz oscillator the output of TCO providing the clock for TC1 and the output of TC1 providing the clock for TC2 You can connect TCO and TC2 clock sources to an external clock through the Primary external I O expansion connector J3 or you can set TCO and TC2 to be clocked by the onboard 8 MHz oscillator Fig 1 5 shows a block diagram of the counter timer circuitry to help you with these connections The SYNC jumper field connects the source for the SYNC pins of the AD converter chips All the SYNC pins of the AD converters are connected together and selected with this jumper field NOTE W
26. gister 1 Board Setup Register 2 16 bit digital VO port Reserved write write read write write read write read write read write write read write read write read write write write write write read read write read Page 3 RTD Finland Oy 1998 2001 Page 4 Each of the DAS Chips RAM Pointer 00 Base 0 Instruction 0 Base 1 Parameter field for Instruction 0 Base 2 Instruction 1 Base 3 Parameter field for Instruction 1 Base 4 Instruction 2 Base 5 Parameter field for Instruction 2 Base E Instruction 15 Base F Parameter field for Instruction 15 RAM Pointer 01 Base 0 1 Comparison Limit 0 Base 1 1 Polarity of Comp intr Sign of Limit 0 Base 2 1 Comparison Limit 1 Base 3 1 Polarity of Comp intr Sign of Limit 1 Base E 1 Comparison Limit 15 Base F 1 Polarity of Comp intr Sign of Limit 15 RAM Pointer 10 Base 0 2 Comparison Limit 0 Base 1 2 Polarity of Comp intr Sign of Limit 0 Base 2 2 Comparison Limit 1 Base 3 2 Polarity of Comp intr Sign of Limit 1 Base E 2 Comparison Limit 15 Base F 2 Polarity of Comp intr Sign of Limit 15 Base 10 DAS Configuration Register 1 Base 11 DAS Configuration Register 2 Base 12 DAS Interrupt mask Register 1 Base 13 DAS Interrupt mask Register 2 Base 14 DAS Interrupt Enable Register 1 Base 15 DAS Interrupt Enable Register 2 Base 16 DAS Timer Register 1 Base 17 DAS Timer Register 2 Base 18 DAS Conversion FIFO low Byte Base 19 DAS Conversion FIFO h
27. he 4 chips has a active interrupt condition it s interrupt request line will keep the global DAS IRQ line active This also means any of the chips may assert the interrupt request If you have enabled interrupts on multiple chips you must read the interrupt status registers of all the chips with enabled interrupts when a DAS interrupt occurs Failure to DM5414 DM6414 RTD Finland Oy 1998 2001 Page 19 do so may keep the interrupt request line active high because one of the DAS chips may still have a pending non serviced interrupt condition Note The IRQ lines are grouped as follows from left to right IRQ11 IRQ10 IRQ7 IRQ5 SPP ADAS TIMERN oletelolololdlolole Fig 1 6 Interrupt line factory setting DAS interrupt set at IRQS Other interrupts are disabled REF DAS 5V Reference source selection Factory settings Ratiometric The DAS chips 5V input voltage range can use two reference techniques 1 Absolute reference where a precision 5 00V reference is used at the Vref and GND to Vref 2 Ratiometric reference where the analog supply 5V is connected to the Vref and GND to Vref In ratiometric systems the analog input voltage is proportional to the one used for the A D converters reference voltage When this is the system analog power supply it relaxes the system reference requirements since the analog input voltage and the A D converter reference voltage change together This maintains the same input c
28. he interrupt vector table the processor starts to execute code from the new Code Segment CS and from the new Instruction Pointer IP When the interrupt routine is completed the old CS and IP are popped from the system stack and the program execution continues from the point it was interrupted Using Interrupt in your Program Adding interrupt support to your program is not as difficult as it may seem especially when programming under DOS The following discussion will cover programming under DOS Note that even the smallest mistake in your interrupt program may cause the computer to hang up and will only restart after a reboot This can be frustrating and time consuming Writing an Interrupt Service Routine ISR The first step in adding interrupts to your software is to write an interrupt service routine DM5414 DM6414 RTD Finland Oy 1998 2001 Page 56 ISR This is the routine that will be executed automatically each time an interrupt request occurs for the specified IRQ An ISR is different from other subroutines or procedures First on entrance the processor registers must be pushed onto the stack before anything else Second just before exiting the routine you must clear the interrupts on the DM5414 DAS chips and write the EOI command to the interrupt controller Finally when exiting the interrupt routine the processor registers must be popped from the system stack and you must execute the IRET assembly instruction This ins
29. hen installing jumpers on this header make sure that only one jumper is installed in each group of the CLK pins OOo O x O MM Or 1 UN CN CN NoOrMA lt mOOD rro OD OxOOXxXA Xx x OL a ol lolol lolol lo CLKO CLK2 PCLK SYNC EG2 Fig 1 4 8254 Counter Timer Clock Source Jumpers Labels are not present on the board due to lack of space DM5414 DM6414 RTD Finland Oy 1998 2001 Page 18 VO CONNECTOR 5 EXT CLK pin45 EXT GATE 1 pind TIC OUT 1 pint T C OUT 2 pin44 TRIGGER IN pin39 EXT GATE 2 pin46 Fig 1 5 User Timer Counter Circuit diagram IRQ 1 Timer Interrupt Channel select Factory settings Interrupt Channel Disabled IRQ 2 DAS Interrupt Channel select Factory settings Interrupt 5 IRQ 3 Timer Interrupt Channel select Factory settings Interrupt Channel Disabled The header connectors shown in Figure 1 6 lets you connect the output of board interrupt sources to an interrupt channel To activate a channel you must install a jumper vertically across the desired IRQ channel s pins To determine which DAS chip has caused an interrupt and on what condition you must read the interrupt status registers BASE 14 and BASE 15 of each DAS chip with enabled interrupts Reading these registers will clear all interrupt flags of the interrupt status register of the DAS chip All the 4 DAS chips are connected together to one external interrupt request line with positive OR logic If any of t
30. igh Byte Base 1A DAS Limit 1 Status Register Base 1B DAS Limit 2 Status Register DM5414 DM6414 RTD Finland Oy 1998 2001 Page 5 Programming the DM5414 Clearing and setting bits in a port A D conversions Interrupts What is an interrupt Interrupt request lines 8259 Programmable interrupt controller Interrupt mask register IMR End Of Interrupt EOD Command What exactly happens when an interrupt occurs Using interrupts in your program Writing an interrupt service routine ISR Saving the startup IMR and interrupt vector Common Interrupt mistakes D A Conversions Timer Counters Digital I O APPENDIX A DM5414 DM6414 Specifications DM5414 DM6414 RTD Finland Oy 1998 2001 Page 6 List of Illustrations DM5414 DM6414 RTD Finland Oy 1998 2001 Page 7 INTRODUCTION DM5414 DM6414 RTD Finland Oy 1998 2001 Page 8 The DM6414 analog digital dataModule will turn your PC 104 cpuModule or other PC 104 computer into a low power multifunction high performance data acquisition and control system This user s manual describes the operation of the DM5414 DM6414 PC 104 Analog Digital Interface board Some of the key properties of the DM5414 DM6414 include 32 single ended or 16 differential analog input channels 4 independent 12 bit low power A D chips with 87 ksample throughput 0 2 5V or 0 5V input ranges Each A D chip features Data acquisition sequencer 32 sample conversion FIFO 16 bit Data acquisition timer Windo
31. ion of Port 1 digital lines Bit 3 Selects the digital interrupt mode event any Port O bits change state or match port 0 match the preprogrammed value in the Compare Register at address BA 27 Bit 4 Disables Enable digital interrupts Bit 5 Sets the clock rate at which the digital lines are sampled when in the digital interrupt mode Available clock source is the 4 MHz system clock When a digital input line changes state it must stay stable for two edges of the clock pulse before it s recognized and before an interrupt can be generated This feature eliminated noise glitches that can cause a false state change on an interrupt line and cause an unwanted interrupt Bit 6 Read only digital IRQ status Bit 7 Read only digital strobe status BA 28 DAC channel 1 in selected chip register low byte BA 29 DAC channel 1 in selected chip register high byte BA 2A DAC channel 2 in selected chip register low byte BA 2B DAC channel 2 in selected chip register high byte Writing to the register pairs will store the data into the currently enabled D A channels selected in the address BA 21 bits 0 and 1 These bits enable the D A converter chips as follows BA 21 DAC chip enable bit definitions D A converters are all disabled channels 1 amp 2 in DAC chip 1 channels 3 amp 4 in DAC chip 2 Channels 1 2 3 and 4 in both chips e olo p aS Example Write data to DAC channel 3 Step 1 Enable DAC chip 2 by writing
32. ital Expansion Connector AIN17 AIN18 AIN19 AIN20 AIN21 AIN22 AIN23 AIN24 AOUT3 AOUT4 AGND IN7 IN6 INS IN4 IN3 IN2 INI INO EXT_SYNC IN EXT GATE 1 SYNC IN OUT EXT CLOCK 12V VCC 12V VSS 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 4 43 45 47 49 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 AIN25 AIN26 AIN27 AIN28 AIN29 AIN30 AIN31 AIN32 AGND AGND AGND OUT7 OUT6 OUTS OUT4 OUT3 OUT2 OUTI OUTO DGND T C OUT 1 T C OUT 2 EXT GATE 2 5V DGND Fig 2 4 Secondary expansion connector pinout J4 DM5414 DM6414 RTD Finland Oy 1998 2001 Page 31 Connecting the analog inputs The analog inputs on this module can be set for single ended or differential operation All channels can be configured to work in a differential mode but only those channels that are grouped to one DAS chip can be differential i e channels 1 8 9 16 16 24 and channels 25 32 Single ended When the input channels are configured for single ended operation connect the high side of the signal to one of the analog input channels AIN1 AIN32 Figure 2 5 shows how these connections are made Differential When operating in this mode your signal source may or may not have a separate ground reference First connect the high side of the analog signal to the selected analog
33. le 1 1 Factory configured jumper settings DM5414 DM6414 RTD Finland Oy 1998 2001 Page 14 rieTrrrericel Leer e m Dekcenec darsnuia SIA Lone Auris aa ai ipa peng 4 om AA isesi Bi Ri t Fig 1 1 DM6414 Board Layout showing Factory Configured settings DM5414 DM6414 RTD Finland Oy 1998 2001 Page 15 This page is left intentionally blank DM5414 DM6414 RTD Finland Oy 1998 2001 Page 16 BA Base Address Factory Setting 1A0h The most common cause of failure when you are first setting up your module is address contention Some of your computers I O space is already occupied by other internal I O devices and expansion boards When the DM5414 attempts to use it s reserved I O addresses already used by another peripheral device erratic performance may occur and data read from the board may be corrupted To avoid this problem make sure you set up the base address first using the two jumpers which let you choose from 4 different I O addresses in your computers I O Should the factory installed setting of 1A0h be unusable for your system configuration you may change this setting to another using the options illustrated in Table 1 2 The table shows the switch settings and their corresponding values in hexadecimal values Make sure you verify the correct location of the base address jumpers Jumper 3 is located below jumper 4 with the PC 104 bus connector toward the bottom When the jumper is removed it corresponds to a lo
34. n you need help This manual and all the example programs will provide you with enough information to fully utilize all the features on this board If you have any problems installing or using this board contact our Technical Support Department 358 9 346 4538 during European business hours or send a FAX requesting assistance to 358 9 346 4539 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 DM5414 DM6414 RTD Finland Oy 1998 2001 Page 12 CHAPTER 1 BOARD SETTINGS The DM5414 have jumper settings you can change if necessary to suit your application The module is factory configured as listed in the table and shown on the layout diagram in the beginning of this chapter Should you need to change the module settings use these easy to follow instructions before you stack your module into your PC 104 system DM5414 DM6414 RTD Finland Oy 1998 2001 Page 13 Factory Configured Jumper settings Table 1 1 lists the factory settings of the user configurable jumper settings on the DM5414 DM6414 board Figures 1 1 and 1 2 show the board layout and the location of the factory set jumpers The following paragraphs explain how to change these settings Pay special attention to the settings of the base address jumpers to avoid address contention when you first use your module in your system Jumper BA TIMERS ROH ROH RO E Bs E Tab
35. ocess is repeated This sequence continues indefinitely DM5414 DM6414 RTD Finland Oy 1998 2001 Page 61 Mode 3 Square wave mode Similar to mode 2 except for the duty cycle output this mode is typically used for baud rate generation The output is initially high and when the counter decrements to one half of its initial count the output goes low for the remainder of the count The counter reloads and the output goes high again This process repeats indefinitely Mode 4 Software triggered strobe The output is initially high When the initial count expires the output goes low for one clock pulse and then goes high again Counting is triggered by writing the initial count Mode 5 Hardware triggered strobe The output is initially high Counting is triggered by the rising edge of the gate signal When the initial count has expired the output goes low for one clock pulse and goes high again Digital VO The Advanced Digital I O chip digital I O signals available in connector J3 are programmed according to the discussion earlier on in this chapter The standard 16 bit general purpose digital I O available in connector J4 is directly programmable using standard input and output instructions DM5414 DM6414 RTD Finland Oy 1998 2001 Page 62 Example programs This section will be completed later See your DM5414 utility disk for the selection of example programs in C code DM5414 DM6414 RTD Finland Oy 1998 2001 Page 63 APPENDIX
36. ode for the same conditions DM5414 DM6414 RTD Finland Oy 1998 2001 Page 20 o _ti col oe m Figure 1 7 shows the 5V reference source selection solder blob B2 This setting is global for all the DAS chips And set to ratiometric factory installed D A converter range select Channels 1 2 and 3 4 DAI_R DA chip 1 range select DA2_R DA chip 2 range select DA3_R DA chip 3 range select DA4_R DA chip 4 range select DA1_R D A converter Range selection Factory settings 10V DA2_R D A converter Range selection Factory settings 10V The jumper field J7 configures D A channel 1 while J8 configures channel 2 These jumper blocks are located next to the primary expansion connector J3 Figure 1 8 illustrates the range jumper for D A channels 1 and 2 J8 Ji Figure 1 8a Range jumper for D A channels 1 and 2 set for 10V range DM5414 DM6414 RTD Finland Oy 1998 2001 Page 21 J Figure 1 8b Range jumper for D A channels 1 and 2 set for 5V range DA3_R D A converter Range selection Factory settings 10V DA4 R D A converter Range selection Factory settings 10V The jumper field J5 configures D A channel 3 while J6 configures channel 4 These jumper blocks are located next to the primary expansion connector J4 Figure 1 9 illustrates the range jumper for D A channels 3 and 4 J5 J Figure 1 9a Range jumper for D A channels 3 and 4 set for 10V range DM5414 DM6414 RTD Finland Oy
37. ote Do NOT force the module onto the connector If the module does not slide into place remove it and try again Wiggling the module or exerting too much pressure on the module can result in damage to the DM5414 or other boards in the stack 6 After the module is installed connect the cable or cables to the analog expansion connectors J3 and J4 When making this connection note that pin one is marked with a square on the top side of the board For twisted pair cables pin is the dark brown wire for standard 50 flat cables pin one is often marked in red 7 Make sure all connections are secure DM5414 DM6414 RTD Finland Oy 1998 2001 Page 28 50 PIN EXPANSION CONNECTORS DM5414 dataModule CMV5 amp 26DX133 Fig 2 1 DM5414 integrated with a PC 104 dataModule stack 3U rack or enclosure installation with a EUROCARD CPU with one DM5414 The PC 104 system can easily be inserted into a 19 rack installation using the CPU as a form factor adapter Assemble your PC 104 dataModules on a RTD single board EUROCARD computer and install the system in a 19 enclosure Multiple DM5414 boards can easily be connected to this system See figure 2 2 for installation ideas 50 PIN EXPANSION CONNECTORS DM5414 50 PIN EXPANSION CONNECTOR datakioduis EUROCARD AT 96 CPU WITH FC 104 EXPANSION BUS Fig 2 2 19 Eurocard rack installation with an integrated PC 104 dataModule and EUROCARD cpuModule computer system DM54
38. ow side of the signal shall be connected to any digital ground GND DM5414 DM6414 RTD Finland Oy 1998 2001 Page 34 CHAPTER 3 HARDWARE DESCRIPTION This Chapter describes the features of the DM5414 hardware The major circuits are the A D chips the D A converters 8254 timer counter the digital I O and the Advanced Bit Programmable Digital I O DM5414 DM6414 RTD Finland Oy 1998 2001 Page 35 The DM5414 has five major circuits the four DAS chips the D A converter circuits the 8254 timer counter the 8 8 general purpose digital I O an the Advanced Bit Programmable Digital I O This chapter describes the hardware which makes up the major circuits Figure 3 1 shows a general block diagram of the DM5414 Advanced Digital 1 0 amp BIT DATABUS J3 Primary I O Connector PCAO4 ISA BUS 8 Fig 3 1 DM5414 Block Diagram A D Conversion Circuitry The DM5414 can interface to 32 single ended or 16 differential input channels with a 0 2 5V or 0 5 0V input range The conversion resolution and conversion rate are fully software configurable The DM5414 is designed using the highly integrated LM12458 low power DAS chip The A D chips are very flexible to program The programming of the chips as well as the hardware description of the A D chips is published as a datasheet reprint of the LM12458 chips Programming these chips is discussed in detail in Chapter 4 Module Operation and Programming DM5414 DM6414 RTD Finland
39. piler do this automatically Put the body of your routine here Read interrupt status register of the DAS chips on your DM5414 board Issue the EOI command to the 8259 by writing 20h to address 20h Pop all registers Most C compilers do this automatically The following C example shows what the shell of your ISR should be like Function new_IRQ_handler Inputs Nothing Returns Nothing Sets the interrupt flag for the EVENT void interrupt far new_IRQ_handler void IRQ flag 1 Indicate to main process interrupt has occurred Your program code should be here Read interrupt status registers that clears interrupts in DAS chip NOTE all active chips must be read since all DAS interrupts are connected together outp 0x20 0x20 Acknowledge the interrupt controller Saving the Startup Interrupt Mask Register JMR and interrupt vector The next step after writing the ISR is to save the startup state of the interrupt mask register IMR and the original interrupt vector you are using The IMR is located in address 21h The interrupt vector you will be using is located in the interrupt vector table which is an array of 4 byte pointers addresses and it is locate din the first 1024 bytes of the memory Segment 0 offset 0 You can read this value directly but it is a better practice to use DOS function 35h get interrupt vector to do this Most C compilers have a special function available for
40. powerful data acquisition performance The converted data can be transferred to PC memory in two ways Data can be transferred using the programmed I O mode or the interrupt mode A special Interrupt mode using the REP INS Repeat Input String instruction supports very fast throughput rates By generating an interrupt when the FIFO is half full a REP INS instruction can be executed transferring data to the PC memory and emptying the DAS FIFO at maximum rate allowed on the data bus The mode of transfer is selected from software Digital to Analog Conversions The Digial to Analog D A circuitry features four independent 12 bit analog output channles with jumper selectable output ranges of OV to 5V OV to 10V 5V 10V Data is programmed into the D A converter by writing two 8 bit bytes the LSB and the MSB The LSB contains the lower 8 data bits 0 7 and the MSB contains the higher data bits 8 11 The D A converter latches can be loaded updated in parallel with a Load command DM5414 DM6414 RTD Finland Oy 1998 2001 Page 10 8254 Timer Counters One 8254 programmable Timer Counter provides three independent 16 bit timer counters to support a wide range of timing and counting functions The source for the timer counters can be the onboard 8 MHz clock or an external oscillator The timers TO and T1 can be cascaded to generate a synchronizing signal to clock all the DAS chips in parallel or the output of these timers can be connect
41. r counter OUT They can be programmed as binary or BCD down counters by writing the appropriate data to the command word as described in Chapter 4 The command word also lets you set up the different modes of operation The six programmable modes are Mode 0 Event Counter Interrupt on Terminal Count Mode 1 Hardware Retriggerable one shot Mode 2 Rate Generator Mode 3 Square Wave Mode Mode 4 Software Triggered Strobe Mode 5 Hardware Triggered Strobe Retriggerable Digital I O Advanced Bit Programmable Digital I O Two separate digital I O ports are available on the DM5414 The primary digital I O port consists of an 8 bit port programmable port and an 8 bit bit programmable port Each bit can be programmed independently to be input or output in this port All the bit programmable I O lines are pulled down with a 10kohm resistor The primary digital I O port is located in the primary Analog Digital I O expansion connector J3 The secondary general purpose digital I O port has 8 latched TTL CMOS compatible outputs and 8 TTL CMOS compatible inputs with 10kohm pulldown resistors The direction and configuration of the general purpose digital I O port is fixed to 8 outputs and 8 inputs The secondary digital I O port is located in the secondary Analog Digital I O expansion connector J4 The internal Advanced Modes of the bit Programmable digital I O port are discussed in detail in Chapter 4 DM5414 DM6414 RTD Finland Oy 1998 2001 Page 39
42. r your IRQ in the IMR This will enable your IRQ Common Interrupt mistakes Remember hardware interrupts are from 8 15 XT IRQ s are numbered 0 7 Forgetting to clear the IRQ mask bit in the IMR Forgetting to send the EOI command after ISR code Disables further interrupts Example on Interrupt vector table setup in C code void far _interrupt new_IRQ1_handler void ISR function prototype define IRQ1_VECTOR 3 Name for IRQ void interrupt far old_IRQ1_dispatcher es ds di si bp sp bx dx cx ax ip cs flags Variable to store old IRQ_ Vector void far _interrupt new_IRQ1_handler void A A a Function init_irq_handlers Inputs Nothing Purpose Set the pointers in the interrupt table to point to l our funtions ie setup for ISR s void init_irq_handlers void _disable old_IRQ1_handler _dos_getvect IRQ1_VECTOR 8 _dos_setvect IRQ1_VECTOR 8 new_IRQ1_handler Gi_old_mask inp 0x21 outp 0x21 Gi_old_mask amp 1 lt lt IRQ1_VECTOR _enable DM5414 DM6414 RTD Finland Oy 1998 2001 Page 59 D A conversions Two individual D A converter chips with two channels each can be programmed to convert 12 bit digital words to an analog output voltage To write to the D A channels you must first enable the D A converter chip by setting the correct D A selection bit in the D A setup register located in address BA 21 After the D A chip is selected you may write your 12 bit data to
43. s 9 16 DAS3 Channels 17 24 DAS4 Channels 25 32 DM5414 DM6414 RTD Finland Oy 1998 2001 Page 9 Any two channels on one DAS chip can be configured for a differential input configu ration This means Channels 1 and 31 cannot work together in differential mode but 1 and 5 can The input voltage ranges 0 2 5V and 0 5V can be selected for each DAS chip This setup is done using solder shorts on the bottom side of the board see Fig 1 12 The 5V reference can be selected with jumpers from two sources 1 A 5 0V absolute reference or 2 The analog 5V supply of the chip Option 2 will provide ratiometric operation of the DAS chips The 5V source selection is global for all the DAS chips see Fig 1 7 The onboard DAS chips can be software programmed for different resolutions These include 9 or 12 bit sign conversions 9 bit conversions are much faster than 12 bit conversions The maximum conversion time for 9 bits is 4 2u s and for 13 bits 8 84s maximum The typical throughput rate at 12 bits sign is 100k samples second Conversions are controlled by the Data acquisitions sequencers on the DAS chips Each conversion can be configured independently and the sequencer program runs automatically sampling data into the onchip FIFO s with no CPU interference Conversion parameters include window comparator monitoring conversion resolution acquisition delay etc The features available for controlling each conversion in random order provides very
44. single command A D conversions are performed by the DAS chips based on the data acquisition seqencer program Conversion data is stored into the DAS chip internal FIFO where it can be retrieved by the host Before the DAS chips can be programmed they must be enabled by writing to the correct DAS enable bits of the register located in address BA 20 After this you may program the internal data acquisition sequencers to make conversions in the way you choose Please refer to the component data sheet for more specific details on the different options and modes of conversions Interrupts What is an interrupt An interrupt is an event that causes the processor in your computer to temporarily halt its current process and execute another routine Upon completion of the new routine control is returned to the original routine at the point where its execution was interrupted Interrupts are a very flexible way of dealing with asynchronous events 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 to do nothing while waiting for a keystroke to occur Thus the interrupt scheme is used and the processor proceeds with other tasks Then when a keystroke occurs the keyboard interrupts the processor and the processor gets the keyboard data placed it into memory and then returns to what it was doing before the interrupt occurred Other common devices that use interr
45. the appropriate D A data storage register Note that this register data will not appear at the outputs before you issue a load instruction This is performed by reading from address BA 21 After this the data in the storage registers is transferred to the analog outputs This feature enables simultaneous updating of all the analog output channels Timer Counters An 8254 programmable interval timer provides three 16 bit 8 MHz timer counters for timing and counting purposes such as frequency measurement event counting and interrupts Two of the timers can be cascaded to generate the pacer clock The remaining timer counter is available for other use Figure 4 1 shows the timer counter circuitry Each timer counter has two inputs CLK in and GATE in and one output timer counter OUT They can be programmed as either binary or BCD down counters by writing the appropriate data to the 8254 Control word as described in the I O map description earlier in this chapter One of the two clock sources the onboard 8 MHz crystal oscillator or the external clock J3 pin 45 can be selected as the clock input to TCO or TC1 The diagram shows how these clock sources are connected to the timer counters Two gate sources are available at the I O connector J3 pin 41 and J3 pin 46 When the gate is disconnected an onboard pull up resistor automatically pulls the gate high enabling the timer counters The output from timer counter 1 is available at the T
46. truction pops the CS IP and processor flags from the system stack These were pushed onto the stack when entering the ISR Most compilers allow you to identify a function as an interrupt type and will automatically add these instructions to your ISR with one exception most compilers do not automatically add the EOI command to the function you must do it yourself Other than this and a few exceptions discussed below you can write your ISR as any code routine It can call other functions and procedures in your program and it can access global data If you are writing your first ISR we recommend you stick to the basics just something that enables you to verify you have entered the ISR and executed it successfully For example set a flag in your ISR and in your main program check for the flag Note If you choose to write your ISR in in line Assembly you must push and pop registers correctly and exit the routine with the IRET instruction instead of the RET instruction There are a few precautions you must consider when writing ISR s The most important is do not use any DOS functions or functions that call DOS functions from an interrupt routine DOS is not reentrant that is a DOS function cannot call itself In typical programming this will not happen because of the way DOS is written But what about using interrupts Then you could have the situation such as this in your program If DOS function X is being executed when an interrupt occurs
47. tware to verify that your module is working DM5414 DM6414 RTD Finland Oy 1998 2001 Page 27 Board installation Keep your board in its antistatic bag until you are ready to install it to your system When removing it from the bag hold the board at the edges and do not touch the components or connectors Please handle the board in an antistatic environment and use a grounded workbench for testing and handling of your hardware Before installing the board in your computer check the jumper settings Chapter 1 reviews the factory settings and how to change them If you need to change any settings refer to the appropriate instructions in Chapter 1 Note that incompatible jumper settings can result in unpredictable board operation and erratic response General installation guidelines 1 Turn OFF the power to your computer 2 Touch the grounded metal housing of your computer to discharge any antistatic buildup and then remove the board from its antistatic bag 3 Select the appropriate standoffs for your application to secure the module when you install it in your system 4 Holding the module by it s edges orient it so that the PC 104 bus connector pin 1 lines up with pin 1 of the expansion connector onto which you are installing the module 5 After carefully positioning the module so that the card edge connector is resting on the expansion connector gently and evenly press down on the module until it is secured on the connector N
48. upts are network cards serial ports etc Your DM5414 can interrupt the main processor when a DAS chip generates an interrupt or by the timer counter Pacer clock By using interrupts you can write powerful code to interface DM5414 board Interrupt request lines To allow different peripheral devices to generate interrupts on the same computer the PC AT bus has interrupt request channels IRQ s A rising edge transition on one of these lines will be latched into the interrupt controller The interrupt controller checks to see if the interrupts are to be acknowledged from that IRQ and if another interrupt is being processed it decides if the new request should supersede the one in progress or if it has to wait until the one in progress is done The priority level of the interrupt is determined by the number of the IRQ IRQO has the highest priority IRQ15 the lowest Many of the IRQ s are used by the standard system resources IRQO is dedicated for the internal timer IRQ1 is dedicated to the keyboard input IRQ3 for serial port COM2 and IRQ4 for serial port COM1 Often interrupts 2 5 and 7 are free for the user DM5414 DM6414 RTD Finland Oy 1998 2001 Page 55 8259 Programmable Interrupt Controller The chip responsible for handling interrupt requests in a PC is the 8259 Interrupt Controller To use interrupts you will need to know how to read and set the 8259 s internal interrupt mask register IMR and how to send the end of interrupt EO
49. w comparators Auto calibration Software enabled interrupts SYNC in and SYNC out for parallel sampling of up to 4 channels per board 16 Digital I O 8 bit programmable direction 8 port programmable direction 16 Digital I O latched 8 Out 8 in Three 8254 based 16 bit Timer Counters free for the user Four 12 bit D A channels with dedicated grounds 5V 10V 0 S5V 0 10V Volt output ranges Single 5V operation Support for direct PC 104 interface with all RTD dataModules and front end boards PC 104 compliant form factor DM5414 is XT bus DM6414 is AT bus version RTD IDAN frame compatible The following paragraphs briefly describe the major features of the DM5414 A more detailed discussion is included in Chapter 3 Hardware description and in Chapter 4 Board operation and programming The board setup is described in Chapter 1 Board Settings Analog to Digital Conversion The Analog to Digital circuitry consists of 4 independent 12 bit sign integrated A D converters These converters function independently of each other and can have different setups acquisition speeds and input ranges The analog input channels are divided between two 50 pin expansion connectors Channels 1 16 are located on the Primary connector J3 channels 17 32 are located on the Secondary connector J4 The analog input channels are dedicated to the 4 A D converter chips called DAS1 DAS2 DAS3 DAS4 DAS1 Channels 1 8 DAS2 Channel

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