Standby Mode - Panasonic MN101L Series User Manual

4.2.3

STANDBY Mode

The transition from CPU operating mode (NORMAL/SLOW) to STANDBY mode (HALT/STOP) is executed by
the program. CPU wakes up from STANBY mode by the interrupt. Figure:4.2.9 shows the flow diagram of transi-
tion to/from STANDBY mode.
Before the transition to STANDBY mode, the following settings are required:
1. Set the PSW.MIE and xICR.IE to "0" to disable all maskable interrupts.
2. Select the interrupt source to wake up CPU from STANBY mode and set only the corresponding xICR.IE to
"1". Set the PSW.MIE to "1".
3. Set STANBY mode in the CPUM.
Interrupt of return factor occured
NORMAL / SLOW
mode
Disable all interrupts
Enable interrupt which
triggers return
Set HALT / STOP
mode
HALT / STOP
mode
(
NORMAL/SLOW
mode
Figure:4.2.9 Transition to/from STANDBY Mode
Set the PSW.MIE to "0",
and set all interrupt enable bits (xICR.IE) to "0".
Set the xICR.IE of the return factor to "1",
and set PSW.MIE to "1".
Watchdog timer
(
HALT0/1/2/3: continue counting
STOP: stop counting
When returning from HALT2 / STOP mode,
wait for oscillation to stabilize
Watchdog timer
(
HALT0/1/2/3: continue counting
STOP: restart counting
Interrupt service routine
Chapter 4
Clock/ Mode/ Voltage Control
)
(
)
Mode Control Function IV - 19