GMS81C1404 Datasheet, PDF (72/93 Pages) Hynix Semiconductor – 8-BIT SINGLE-CHIP MICROCONTROLLERS

GMS81C1404/GMS81C1408
INPUT PIN
V_DD
V_DD
internal
pull-up
i
GND
V_DD
X
Weak pull-up current flows
VDD
O
OPEN
O
INPUT PIN
OPEN
i
VDD
i=0
O
Very weak current flows
X
i=0
GND
O
When port is configure as an input, input level should
be closed to 0V or 5V to avoid power consumption.
Figure 19-7 Application Example of Unused Input Port
OUTPUT PIN
ON
OFF _i
GND
X
ON
OPEN
OFF
O
V_DD
ON
O ^OFF
In the left case, much current flows from port to GND.
OUTPUT PIN
ON
OFF _i
V_DD
L
GND
OFF
ON i=0
V_DD
L
GND
X
O
In the left case, Tr. base current flows from port to GND.
To avoid power consumption, there should be low output
to the port.
Figure 19-8 Application Example of Unused Output Port
70
June. 2001 Ver 1.2