Manual PCI-DIO-24DH
15
Chapter 6: Programming
These cards are I/O-mapped devices that are easily configured from any language and any language can
easily perform digital I/O through the card's ports. This is especially true if the form of the data is byte or
word wide. All references to the I/O ports would be in absolute port addressing.
Developing Your Application Software
If you wish to gain a better understanding of the programs on diskette, then the information in the
following paragraphs will be of interest to you. Refer to the data sheets and 8255-5 specification in
Appendix A.
A total of 16 register locations are used by these cards. With all counters (S03), the total becomes 32
register locations.
Address
Port Assignment
Operation
Base Address
PA Group 0
Read/Write
Base A1
PB Group 0
Read/Write
Base A2
PC Group 0
Read/Write
Base A3
Control byte
Write Only
Base A4
Unused
Base A5
Unused
Base A6
Unused
Base A7
Unused
Base A8
Unused
Base A9
Unused
Base AC
Enable/Disable Buffer
Write Only
Base AD
Disable Interrupts
Write Only
Base AE
Enable Interrupts
Write Only
Base AF
Clear Interrupt latch
Write Only
Base A10 Counter/Timer A0
Read/Write
Base A11 Counter/Timer A1
Read/Write
Base A12 Counter/Timer A2
Read/Write
Base A13 Counter/Timer A Control
Read/Write
Base A14 Counter/Timer B0
Read/Write
Base A15 Counter/Timer B1
Read/Write
Base A16 Counter/Timer B2
Read/Write
Base A17 Counter/Timer B Control
Read/Write
Base A18 Counter/Timer C0
Read/Write
Base A19 Counter/Timer C1
Read/Write
Base A1A Counter/Timer C2
Read/Write
Base A1B Counter/Timer C Control
Read/Write
Table 6-1:
Address Assignment Table
