Fujitsu FR30 - page 120

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CHAPTER 3 CLOCK GENERATOR AND CONTROLLER
[Example of setting the maximum gear speed]
■Returning from the Sleep State
An interrupt or resetting can be used to return from the sleep state.
❍Return by way of an interrupt
When the enable bit for the interrupt, which is one of th e p eriph er al fun ct ions, is o n, a pe ri ph eral
interrupt can be used to return from the sleep state.
The procedure for returning from the stop state to the normal run state is as follows:
Interrupt generation --> restart of internal bus clock supply --> restart of internal CPU
clock supply
Program execution after clock supply is as follo ws:
• When the level of the caused interrupt is enabled by the I flag of CPU ILM
• The progr am saves the register, fetches the interrupt vector, and execut es processing
beginning from the interrupt processing routine.
• When the level of the caused interrupt is disabled by the I flag of CPU ILM
• The pro gram execute s instruct ions begin ning from th e instruct ion follow ing the instr uction
that caused transition to the sleep state.
❍Return by way of a reset request
The procedure for returning from the stop state to the normal run state is as follows:
Occurrence of internal reset --> restart of internal bus clock supply --> restart of internal
CPU clock supply --> reset vector fetch --> restart of instruction execution from reset
entry address
<Notes>
• When a perip heral interru pt is used as a DMA transfer request, the inter rupt can not be us ed
to return from the sleep state.
• If a per ipheral inte rrupt request h as already been issued when the ST CR register bits 7 and
6 are written, transition to the sleep state does not occur. If a DMA request and sleep
LDI:20 #GCR,R0
LDI:8 #0000001 1b,R1 ; CHC=1,CPU=peripheral gear ratio
STB R1,@R0 ; If DBLON=0
LDI:20 #STCR,R0
LDI:8 #0101000 0b,R1 ; SLEP=1
STB R1,@R0
NOP ;
NOP ;
NOP ;
NOP ;
NOP ;
NOP ;