Figure B-9. Port C Pin Assignments On I/O Connector When Port C Configured For Mode 1 Output - National Instruments PCI-DIO-96 User Manual

Appendix B
0
At the digital I/O connector, port C has the pin assignments shown in Figure B-9 when in
mode 1 output. Notice that the status of ACKA* and ACKB* are not included when port C
is read.

Figure B-9. Port C Pin Assignments on I/O Connector when Port C Configured for Mode 1 Output

Mode 1 Strobed Output Programming Example
The following example shows how to configure PPI A for mode 1 output.
Write (8255Cnfg, 0xA0)
Write (8255Cnfg, 0x0D)
Loop until the INTRA (PC3) and OBFA* (PC7) status flags are set,
Write (PortA, Data)
© National Instruments Corporation
Register-Level Programming — Port C Status-Word Bit Definitions for Output (Ports A and B)
INTRB Interrupt Request Status for Port B—This status flag,
which operates only when INTEA is high, indicates that
port B has acquired data and is ready to be read. If you
have enabled interrupts (by setting INTEN and the
appropriate bit in Interrupt Control Register 2), this status
flag also indicates that an interrupt request is pending for
port B.
Group A
Group B
Set mode 1—port A is an output
Set PC6 to enable the INTRA status flag
indicating that the 82C55A is ready for a
transfer and that the output buffer is not
full
Write data to port A
PC7 OBFA*
PC6 ACKA*
PC5 I/O
PC4 I/O
PC3 INTRA
PC2 ACKB*
PC1 OBFB*
PC0 INTRB
B-25 PCI-DIO-96/PXI-6508/PCI-6503 User Manual