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Chapter 3 Theory of Operation
PC-LPM-16/PnP User Manual
3-8
National Instruments Corporation
Digital I/O Circuitry
The PC-LPM-16PnP has 16 digital I/O lines that are TTL-compatible.
Pins DIN<0..7> of the I/O connector are digital input lines, and pins
DOUT<0..7> are digital output lines. These lines are monitored or
driven by the Digital Input Register or the Digital Output Register,
respectively. Reading the Digital Input Register returns the current state
of the DIN<0..7> lines. Writing to the Digital Output Register drives
the new value onto the DOUT<0..7> lines. The external device may
drive the EXTINT* signal to indicate the readiness of data transfer.
Figure 3-4.
Digital I/O Circuitry Block Diagram
PC I/O Channel
8
/
8
/
I/O Connector
EXTINT*
8
/
8
/
I/O RD
I/O WR
DIN <0..7>
DOUT<0..7>
Digital
Input
Register
Digital
Output
Register
Status
Register 1
Plug and
Play
Interrupt
Interface
a.Book : g.chapter 3 Page 8 Wednesday, November 20, 1996 6:36 PM
Summary of Contents for PC-LPM-16/PnP
Page 50: ...Appendix B MSM82C53 Data Sheet PC LPM 16 PnP User Manual B 2 National Instruments Corporation ...
Page 51: ...Appendix B MSM82C53 Data Sheet National Instruments Corporation B 3 PC LPM 16 PnP User Manual ...
Page 52: ...Appendix B MSM82C53 Data Sheet PC LPM 16 PnP User Manual B 4 National Instruments Corporation ...
Page 53: ...Appendix B MSM82C53 Data Sheet National Instruments Corporation B 5 PC LPM 16 PnP User Manual ...
Page 54: ...Appendix B MSM82C53 Data Sheet PC LPM 16 PnP User Manual B 6 National Instruments Corporation ...
Page 55: ...Appendix B MSM82C53 Data Sheet National Instruments Corporation B 7 PC LPM 16 PnP User Manual ...
Page 56: ...Appendix B MSM82C53 Data Sheet PC LPM 16 PnP User Manual B 8 National Instruments Corporation ...
Page 57: ...Appendix B MSM82C53 Data Sheet National Instruments Corporation B 9 PC LPM 16 PnP User Manual ...