8.0 PROGRAMMING SUMMARY
8.1 LOAD INTERRUPT VECTOR
8.2 SET MODE
Ml
Mo
X X
Ml
Mo
Mode
0 0 Output
0 Input
1 0 Bidirectional
I
Bit Control
When selecting Mode
3,
the next word must set the I/0 Register:
I/0
1
I 1/0o
1/0 = 1 Sets bit
to
Input
1/0
= 0 Sets bit to O
utput
8.
3 SET INTERRUPT CONTROL
Int
AND/
Hig
h/
Ma
sk
0 I
Enable
OR
Low Follows
Used in Mode 3 only
1 I
If
th
e "mask follows" bit
is
high, the next control word written
to
the
port
must be the ma
sk
:
MBo
MB
= 0, Monitor bit
MB
=
I,
Mask bit from being monitored
125
Al
so, the interrupt enable flip flop
of
a
port
may be set or
re
s
et
without modifying the
re
st
of
the interrupt control
word by using the following command:
I
Int
Enable
X
X X
0
0
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