HD64F2168 Datasheet, PDF (785/874 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer

23.8 Subsleep Mode
The CPU makes a transition to subsleep mode when the SLEEP instruction is executed in
subactive mode with the SSBY bit in SBYCR cleared to 0, the LSON bit in LPWRCR set to 1,
and the PSS bit in TCSR (WDT_1) set to 1.
In subsleep mode, the CPU is stopped. Peripheral modules other than TMR_0, TMR_1, WDT_0,
and WDT_1 are also stopped. The contents of the CPU’s internal registers, several on-chip
peripheral module registers, and on-chip RAM data are retained and the I/O ports retain their
values before transition as long as the prescribed voltage is supplied.
Subsleep mode is exited by an interrupt (interrupts by on-chip peripheral modules, NMI, IRQ0 to
IRQ15, KIN0 to KIN15, or WUE8 to WUE15), the RES pin input, or the STBY pin input.
When an interrupt occurs, subsleep mode is exited and interrupt exception handling starts.
In the case of an IRQ0 to IRQ15 interrupt, subsleep mode is not exited if the corresponding enable
bit has been cleared to 0 or the interrupt is masked by the CPU. In the case of a KIN0 to KIN15 or
WUE8 to WUE15 interrupt, subsleep mode is not exited if input is disabled or the interrupt is
masked by the CPU. In the case of an interrupt from the on-chip peripheral modules, subsleep
mode is not exited if the interrupt enable register has been set to disable the reception of that
interrupt or the interrupt is masked by the CPU.
When the RES pin is driven low, system clock oscillation starts. Simultaneously with the start of
system clock oscillation, the system clock is supplied to the entire LSI. Note that the RES pin
must be held low until clock oscillation is settled. If the RES pin is driven high after the clock
oscillation settling time has passed, the CPU begins reset exception handling.
If the STBY pin is driven low, the LSI enters hardware standby mode.
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