HMS81C2012A Datasheet, PDF (79/107 Pages) List of Unclassifed Manufacturers – CMOS Single-Chip 8-Bit Microcontroller with A/D Converter & VFD Driver

HMS81C2012A/2020A
17. Power Saving Mode
For applications where power consumption is a critical
factor, device provides four kinds of power saving func-
tions, STOP mode, Sub-active mode and Wake-up Timer
mode (Stand-by mode, Watch mode). Table 17-1 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
Sub-active Mode
Retain
Retain
Retain
Operation
Operation
Stop
Oscillation
Operation
0
Wake-up Timer Mode
Stand-by Mode Watch Mode
Retain
Retain
Retain
Retain
Retain
Retain
Stop
Stop
Operation
Operation
Oscillation
Stop
Stop
Oscillation
÷ 2048 only
÷ 2048 only
1
1
Table 17-1 Power Saving Mode
The power saving function is activated by execution of
STOP instruction and by execution of STOP instruction af-
ter setting the corresponding status (WAKEUP) of
CKCTLR. We shows the release sources from each Power
Saving Mode
Release Source
RESET
RCWDT
EXT.INT0
EXT.INT1
Timer0
STOP Mode
O
O
O
X
Sub-active
Mode
O
O
Wake-up Timer Mode
Stand-by Mode Watch Mode
O
O
O
O
O
O
O
X
O
O
Table 17-2 Release Sources from Power Saving Mode
SEP. 2004 Ver 2.00
75