Fujitsu FR81S Manuel D’Utilisation
CHAPTER 30: POWER CONSUMPTION CONTROL
6. Example of Use
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : POWER CONSUMPTION CONTROL
FUJITSU SEMICONDUCTOR CONFIDENTIAL
55
6. Example of Use
Examples of activation of sleep mode and standby mode are shown below.
Figure 6-1 Examples of activation of sleep mode and standby mode
- Able to recover on interrupts from peripherals that also operate in sleep mode.
- (Example) Enable interrupts from PPG.
- (Example) Enable interrupts from the base timer
- (Example) Because interrupts from an interval timer are already begin
-
serviced in order to clear the watchdog timer regularly, perform no preparation
in particular.
- Change to the main clock if using the PLL clock.
- Configure the pin states before entering standby.
- Clear the watchdog timer.
- [Example] Sample program that activates watch mode
LD1 #value_of_time, R0: TIMER bit = '1', SLVL setting
LD1 #_STBCR,R12
STB R0,@R12 ; Write
LDUB @R12,R0 ; Read (Enter watch)
MOV R0,R0 ; Dummy operation to adjust pipeline
NOP ; Dummy operation to adjust pipeline
- Able to recover on interrupt requests from external interrupt pins and
interrupt requests from the NMI.
- The main clock oscillation stabilization wait time is required in stop mode.
- Return to the clock settings immediately before entering standby as
required.
- Able to recover on interrupts from peripherals that also
operate in sleep mode.
- Not required. Enters sleep from any of the main, PLL, or sub
clock modes.
- Clear the watchdog timer.
- [Example] Sample program that activates sleep mode
LD1 #value_of_sleep, R0 : SLEEP bit = '1', SLVL setting
LD1 #_STBCR,R12
STB R0,@R12 ; Write
LDUB @R12,R0 ; Read (Enter sleep)
MOV R0,R0 ; Dummy operation to adjust pipeline
NOP ; Dummy operation to adjust pipeline
Example when using sleep mode Example When using standby
- Able to recover on interrupts from external interrupt pins or the NMI pin.
- (Example) Enable external interrupts.
- (Example) Issue instruction so that the NMI pin is used for a companion
chip.
MB91520 Series
MN705-00010-1v0-E
1142