MSM80C154S/83C154S/85C154HVS
198
Figure 5-6 Quasi-bidirectional port accelerator circuit operation time chart
S1 S2 S3 S4 S5 S6 S1 S2 S3 S4 S5 S6
M1
S1
XTAL1
1-
0-
ALE
1-
0-
W-PORT
1-
0
PORT-OUT
1-
0
*P1·2·3TR-ON
1-
0
CPU-BUS
1
0
S2S6
PSEN
1
0
PORT DATA="0" PORT DATA="1"
*
M1
