User Manual

© Sealevel Systems, Inc.
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PIO-48.PC104 User Manual
I/O Control Word
Each port may be configured as either Input or Output. This is accomplished by
writing the correct Control Word (CW) to the proper register.
CWnD0 Port C1 lower nibble (bits 0-3) 1 = input 0 = output 1 on power up
CWnD1 Port B1 1 = input 0 = output 1 on power up
CWnD2
0 or 1 (no effect)
CWnD3 Port C1 upper nibble (bits 4-7) 1 = input 0 = output 1 on power up
CWnD4 Port A1 1 = input 0 = output 1 on power up
CWnD5
0 or 1 (no effect)
CWnD6 0 or 1 (no effect)
CWnD7
0 or 1 (no effect)
Control Word (X = 0) Hex Value Port Setup
7 6 5 4 3 2 1 0
A B C Upper C Lower
X X X 0 0 X 0 0 80 Out Out Out Out
X X X 0 0 X 0 1 81 Out Out Out In
X X X 0 0 X 1 0 82 Out In Out Out
X X X 0 0 X 1 1 83 Out In Out In
X X X 0 1 X 0 0 88 Out Out In Out
X X X 0 1 X 0 1 89 Out Out In In
X X X 0 1 X 1 0 8A Out In In Out
X X X 0 1 X 1 1 8B Out In In In
X X X 1 0 X 0 0 90 In Out Out Out
X X X 1 0 X 0 1 91 In Out Out In
X X X 1 0 X 1 0 92 In In Out Out
X X X 1 0 X 1 1 93 In In Out In
X X X 1 1 X 0 0 98 In Out In Out
X X X 1 1 X 0 1 99 In Out In In
X X X 1 1 X 1 0 9A In In In Out
X X X 1 1 X 1 1 9B In In In In