Figure B-2. Control Word Formats For The 82C55A - National Instruments PCI-DIO-96 User Manual

Control Word Flag
1 = Mode Set
Mode Selection
00 = Mode 0
01 = Mode 1
1X = Mode 2
Port A
1 = Input
0 = Output
Port C
(high nibble)
1 = Input
0 = Output
Control Word Flag
0 = Bit Set/Reset
Unused
© National Instruments Corporation
Appendix B
Group A
D7 D6 D5 D4
a. Control Word Flag, Mode Set (bit 7 = 1)
D7 D6 D5 D4
b. Control Word Flag, Bit Set/Reset (bit 7 = 0)

Figure B-2. Control Word Formats for the 82C55A

Register-Level Programming — Register Map and Description
Group B
D3 D2 D1
D3 D2 D1
B-7 PCI-DIO-96/PXI-6508/PCI-6503 User Manual
D0
Port C
(low nibble)
1 = Input
0 = Output
Port B
1 = Input
0 = Output
Mode Selection
0 = Mode 0
1 = Mode 1
D0
Bit Set/Reset
1 = Set
0 = Reset
Bit Select
(000)
(001)
(010)
:
:
(111)