20.3 Sleep Mode
20.3.1 Transition to Sleep Mode
When the SSBY bit is cleared to 0 in SYSCR, execution of the SLEEP instruction causes a
transition from the program execution state to sleep mode. Immediately after executing the SLEEP
instruction the CPU halts, but the contents of its internal registers are retained. The DMA
controller (DMAC), refresh controller, and on-chip supporting modules do not halt in sleep mode.
Modules which have been placed in standby by the module standby function, however, remain
halted.
20.3.2 Exit from Sleep Mode
Sleep mode is exited by an interrupt, or by input at the
RES
or
STBY
pin.
Exit by Interrupt: An interrupt terminates sleep mode and causes a transition to the interrupt
exception handling state. Sleep mode is not exited by an interrupt source in an on-chip supporting
module if the interrupt is disabled in the on-chip supporting module. Sleep mode is not exited by
an interrupt other than NMI if the interrupt is masked by the I and UI bits in CCR and IPR.
Exit by
RES
Input: Low input at the
RES
pin exits from sleep mode to the reset state.
Exit by
STBY
Input: Low input at the
STBY
pin exits from sleep mode to hardware standby
mode.
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