Port b register – National Instruments Low-Cost Multifunction I/O Board for ISA Lab-PC+ User Manual

Page 151

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Appendix D

Register Map and Descriptions

© National Instruments Corporation

D-35

Lab-PC+ User Manual

Port B Register

Reading the Port B Register returns the logic state of the eight digital I/O lines constituting
Port B, that is, PB<0..7>. If Port B is configured for output, the Port B Register can be written to
in order to control the eight digital I/O lines constituting Port B. See Programming the Digital
I/O Circuitry
in Appendix E, Register-Level Programming, for information on how to configure
Port B for input or output.

Address:

Base address + 11 (hex)

Type:

Read-and-write

Word Size:

8-bit

Bit Map:

7

6

5

4

3

2

1

0

D7

D6

D5

D4

D3

D2

D1

D0

Bit

Name

Description

7-0

D<7..0>

8-bit Port B data.

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