User's Manual

INPUT/OUTPUT PORTS
197
READ
N
OFF
P3
ON
R=100kΩ
.
.
P2
ON
R=10kΩ
.
.
P1
ON
R=500Ω
.
.
VCC
INTERNAL
BUS
IOH
(A) When accelerator circuit is activated
READ
N
OFF
P3
ON
R=100kΩ
.
.
P2
ON
R=10kΩ
.
.
P1
OFF
R=500Ω
.
.
VCC
INTERNAL
BUS
IOH
(B) When "1" data is held
OFF
READ
N
ON
P3
R=100kΩ
.
.
P2
R=10kΩ
.
.
P1
R=500Ω
.
.
VCC
INTERNAL
BUS
IOL
(C) When "0" data is held
OFF
OFF
Figure 5-5 Quasi-bidirectional port equivalent circuit