Fujitsu MB90480 Series Hardware Manual page 156

CHAPTER 6 LOW-POWER CONSUMPTION MODE
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Canceling the sleep mode
The low-power consumption control circuit cancels the sleep mode by input of a reset or by an
interrupt.
❍ Restore by a reset
Reset initializes to the main clock mode.
❍ Restore by interrupt
The sleep mode is canceled if an interrupt request whose interrupt level is higher than 7 is
generated in a peripheral circuit, etc., in the sleep mode. After the sleep mode is canceled, the
interrupt is processed with the same method as for ordinary interrupt processing. If interrupts
are accepted by setting the I-flag of the condition code register (CCR), interrupt level mask
register (ILM), or the interrupt control register (ICR), then the CPU executes the interrupts. If the
interrupts cannot be accepted, the CPU continues processing beginning from an instruction next
to the instruction specifying the sleep mode.
Figure 6.5-1 illustrates the canceling of the sleep mode by an interrupt.
Setting interrupt enable flag
from peripheral functions
INT generates (IL<7)
I = 0
ILM < IL
Interrupt executed
Note:
When executing an interrupt, an instruction next to the instruction that specified the sleep mode is
normally executed first before an interrupt request is processed. If a change to the sleep mode
occurs at the same time as an external bus hold request is received, an interrupt may be executed
first before the next instruction is executed.
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Figure 6.5-1 Canceling of sleep mode by interrupt
NO
Sleep not canceled
YES
YES
Next instruction
NO
YES
Executes next instruction
NO
Sleep not canceled
Sleep canceled