Table 14.7 Fast A20 Gate Output Signal
Internal CPU
GA20
HA0
1
Data/Command
H'D1 command
“1” data*1
Interrupt Flag
(PB1)
Remarks
0
0
0
0
0
0
0
0
1
Q
Turn-on sequence
0
1
1
H'FF command
H'D1 command
“0” data*2
Q (1)
Q
1
Turn-off sequence
0
0
1
H'FF command
H'D1 command
“1” data*1
Q (0)
Q
1
Short turn-on sequence
0
1
1/0
Command other than H'FF
and H'D1
Q (1)
1
H'D1 command
“0” data*2
0
0
1
Q
Short turn-off sequence
0
0
1/0
Command other than H'FF
and H'D1
Q (0)
1
1
1
1
1
0
1
H'D1 command
Command other than H'D1
H'D1 command
H'D1 command
H'D1 command
Any data
0
1
0
0
0
0
0
Q
Cancelled sequence
Retriggered sequence
Q
Q
Q
Q
Consecutively executed
sequences
1/0
Q (1/0)
H'D1 command
Notes: *1 Arbitrary data with bit 1 set to 1.
*2 Arbitrary data with bit 1 cleared to 0.
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