FUJITSU MB91F109 FR30 - Manual (Page 117)

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3.10 Standby Mode (Low Power Consumption Mechanism)
[Example of setting the maximum gear speed:]
■ Returning from the Stop State
An interrupt or resetting can be used to return from the stop state.
❍ Return by way of an interrupt
When the interrupt enable bit, which is one of the peripheral functions, is on, a peripheral
interrupt can be caused to return from the stop state.
The procedure for returning from the stop state to the normal run state is as follows:
Interrupt generation --> restart of oscillation circuit operation --> wait for oscillation
stabilization --> restart of internal peripheral clock supply after stabilization --> restart of
internal DMA clock supply --> restart of internal bus clock supply --> restart of internal
CPU clock supply
Program execution after the oscillation stabilization wait time is as follows:
• When the level of the interrupt is enabled by the I flag of CPU ILM
• The program saves the register, fetches the interrupt vector, and executes processing
beginning from the interrupt processing routine.
• When the level of the interrupt is disabled by the I flag of CPU ILM
• The program executes instructions beginning from the instruction following the instruction
that caused the transition to the stop state.
❍ Return by way of the RSTX pin
The procedure for returning from the stop state to the normal run state is as follows:
LDI:20 #GCR,R0
LDI:8 #00000011b,R1 ; CHC = 1, CPU = Peripheral gear
ratio
STB R1,@R0 ; DBLON=0
loop
BTSTH #0010b,@R0 ;
BNE loop ; Wait until DBLAK becomes 0
LDI:20 #STCR,R0
LDI:8 #10010000b,R1 ; STOP=1
STB R1@R0
NOP ;
NOP ;
NOP ;
NOP ;
NOP ;
NOP ;