National Instruments PC-DIO-24

Contents

PC-DIO-24 User Manual viii © National Instruments Corporation

Chapter 4

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