National Instruments PC-DIO-24, User Manual

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Contents
PC-DIO-24 User Manual viii © National Instruments Corporation
Chapter 4
Register-Level Programming
......................................................................................... 4-1
Introduction .................................................................................................................... 4-1
82C55A Modes of Operation ......................................................................................... 4-1
Mode 0 ............................................................................................................... 4-2
Mode 1 ............................................................................................................... 4-2
Mode 2 ............................................................................................................... 4-2
Single Bit Set/Reset Feature .............................................................................. 4-2
Register Map .................................................................................................................. 4-3
Register Descriptions ..................................................................................................... 4-3
Single Bit Set/Reset Feature .............................................................................. 4-4
Programming Considerations......................................................................................... 4-5
Mode 0–Basic I/O .............................................................................................. 4-5
Mode 0 Programming Example ............................................................. 4-6
Mode 1–Strobed Input ....................................................................................... 4-7
Mode 1 Input Programming Example.................................................... 4-9
Mode 1–Strobed Output ..................................................................................... 4-9
Mode 1 Output Programming Example ................................................. 4-11
Mode 2–Bidirectional Bus ................................................................................. 4-12
Mode 2 Programming Example ............................................................. 4-13
Interrupt Programming Examples ...................................................................... 4-14
Interrupt Handling .......................................................................................................... 4-15
Appendix A
Specifications
........................................................................................................................ A-1
Appendix B
I/O Connector
....................................................................................................................... B-1
Appendix C
OKI 82C55A Data Sheet
................................................................................................... C-1
Appendix D
Customer Communication
............................................................................................... D-1
Glossary
............................................................................................................................ Glossary-1
Index
.................................................................................................................................. Index-1