GMS81C2020 Datasheet, PDF (77/92 Pages) Hynix Semiconductor – CMOS Single-Chip 8-Bit Microcontroller with A/D Converter & VFD Driver

Hyundai Micro Electronics
GMS81C2020/GMS81C2120
OUTPUT PIN
ON
OFF _i
GND
X
ON
OPEN
OFF
O
V_DD
ON
OFF
O
In the left case, much current flows from port to GND.
OUTPUT PIN
ON
OFF _i
V_DD
L
GND
OFF
V_DD
L
ON i=0
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 21-3 Application Example of Unused Input Port
Minimizing Current Consumption in Stop Mode
The Stop mode is designed to reduce power consumption.
To minimize current drawn during Stop mode, the user
should turn-off output drivers that are sourcing or sinking
current, if it is practical. Weak pull-ups on port pins should
be turned off, if possible. All inputs should be either as
VSS or at VDD (or as close to rail as possible).
An intermediate voltage on an input pin causes the input
buffer to draw a significant amount of current.
Oscillator
(XI pin)
Internal
Clock
External
Interrupt
BIT
Counter
STOP Instruction Execution
N-2 N-1 N N+1
Normal Operation
N+2
STOP Mode
Clear Basic Interval Timer
00 01
FE FF 00 00
Stabilization Time
t_ST > 20mS
Normal Operation
Figure 21-4 Timing of STOP Mode Release by External Interrupt
Nov. 1999 Ver 0.0
preliminary
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