Fujitsu FR81S User Manual
CHAPTER 30: POWER CONSUMPTION CONTROL
5. Operation
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : POWER CONSUMPTION CONTROL
FUJITSU SEMICONDUCTOR CONFIDENTIAL
24
5.3.4. Activation of Sleep mode
Activation of sleep mode is described below.
To activate sleep mode, follow the steps below.
⋅
Write "001" to bit7:STOP, bit6:TIMER, bit5:SLEEP in the STBCR register.
⋅
Read STBCR
In FR81S core, if the read value will not be used in the next instruction, that instruction is executed before
the read is completed. Perform dummy processing to use the read value in the next instruction so as not to
make the program progress before entering sleep mode.
[Example] Sample program of sleep mode activation
LDI
#value_of_sleep, R0
; SLEEP bit ="1", SLVL setting
LDI
#_STBCR, R12
;
STB
R0, @R12
; Write
LDUB @R12, R0
; Read (activation of sleep mode)
MOV
R0, R0
; Dummy processing for pipeline adjustment
NOP
; Dummy processing for pipeline adjustment
MB91520 Series
MN705-00010-1v0-E
1111