GMS81C2020 Datasheet, PDF (73/92 Pages) Hynix Semiconductor – CMOS Single-Chip 8-Bit Microcontroller with A/D Converter & VFD Driver

Hyundai Micro Electronics
GMS81C2020/GMS81C2120
21. Power Saving Mode
For applications where power consumption is a critical
factor, device provides four kinds of power saving func-
tions, STOP mode, Subactive mode and Wake-up Timer
mode(Standby mode, Watch mode).
Table 21-1 shows the status of each Power Saving Mode.
Peripheral
STOP Mode
RAM
Control Registers
I/O Ports
CPU
Timer0
Oscillation
Sub Oscillation
Prescaler
Entering Condition
[WAKEUP]
Retain
Retain
Retain
Stop
Stop
Stop
Stop
Stop
0
Subactive Mode
Retain
Retain
Retain
Operation
Operation
Stop
Oscillation
Operation
0
Wake-up Timer Mode
Standby Mode Watch Mode
Retain
Retain
Retain
Retain
Retain
Retain
Stop
Stop
Operation
Operation
Oscillation
Stop
Stop
Oscillation
÷ 2048 only
÷ 2048 only
1
1
Table 21-1 Power Saving Mode
The power saving function is activated by execution of
STOP instruction and by execution of STOP instruction
after setting the corresponding status (WAKEUP) of
CKCTLR.
we shows the release sources from each Power Saving
Mode
Release Source
RESET
RCWDT
EXT.INT
EXT.INT1
Timer0
STOP Mode
O
O
O
X
Subactive
Mode
O
O
O
X
Wake-up Timer Mode
Standby Mode Watch Mode
O
O
O
O
O
O
O
O
Table 21-2 Release Sources from Power Saving Mode
Nov. 1999 Ver 0.0
preliminary
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