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.
Control Word (X = 0)
Hex Value
Port Setup
7
6
5
4
3
2
1
0
A
B
C
1
X
X
0
0
X
0
0
80
Out
Out
Out
1
X
X
0
0
X
0
1
81
Out
Out
In
1
X
X
0
0
X
1
0
82
Out
In
Out
1
X
X
0
0
X
1
1
83
Out
In
In
1
X
X
0
1
X
0
0
88
Out
Out
In
1
X
X
0
1
X
0
1
89
Out
Out
In
1
X
X
0
1
X
1
0
8A
Out
In
In
1
X
X
0
1
X
1
1
8B
Out
In
In
1
X
X
1
0
X
0
0
90
In
Out
Out
1
X
X
1
0
X
0
1
91
In
Out
In
1
X
X
1
0
X
1
0
92
In
In
Out
1
X
X
1
0
X
1
1
93
In
In
In
1
X
X
1
1
X
0
0
98
In
Out
In
1
X
X
1
1
X
0
1
99
In
Out
In
1
X
X
1
1
X
1
0
9A
In
In
In
1
X
X
1
1
X
1
1
9B
In
In
In
Interrupt Control
When enabled interrupts are generated on port bit D0 of each A port.
n = port number
IRQENn
interrupt enable
1 = enabled
0 = disabled ( 0 on power up )
IRQCn0
IRQCn1
Interrupt mode select, see table below
Interrupt mode select, see table below
Interrupt Mode Select Table
IRQCn1
IRQCn0
INT Type
0
0
Low level
0
1
High level
1
0
Falling edge
1
1
Rising edge
Summary of Contents for REL-32.PCI
Page 1: ...PIO 96 PCI User Manual 8009...
Page 18: ...Example Circuits...
