r5s77631ay266bgv Renesas Electronics Corporation., r5s77631ay266bgv Datasheet - Page 745

Manufacturer Part Number

r5s77631ay266bgv

Renesas 32-bit Risc Microcomputer Superhtm Risc Engine Family Sh-4a Series

Manufacturer

Renesas Electronics Corporation.

Executing the SLEEP instruction when the STBY bit in STBCR is 1 causes a transition from the

program execution state to software standby mode. In software standby mode, not only the CPU

but also the clock and on-chip peripheral modules halt. However, the clock output from the

CLKOUT pin continues when the CKONE bit in the PLLCR register of the CPG is set to 1. When

the CKONE bit is 0, a low level is output from the CLKOUT pin.

The contents of the CPU and cache registers remain unchanged. Some registers of the on-chip

peripheral modules are initialized.

The procedure for a transition to software standby mode is as follows:

1. Set the STBY bit in STBCR to 1.

2. Execute the SLEEP instruction.

3. Software standby mode is entered and the clocks within the LSI are halted. The output on the

All modules should be stopped before the above procedure is executed.

Software standby mode is canceled by an interrupt (NMI or IRQ/IRL) or a reset.

When an NMI or IRQ, occurs, software standby mode is canceled and the STATUS0 pin goes

low. Thereafter, interrupt exception handling is executed and a code indicating the interrupt source

is set in INTEVT. After branching to the interrupt service routine, clear the STBY bit in the

STBCR register back to 0. Since interrupts are accepted in software standby mode even when the

BL bit in SR is 1, save SPC and SSR to the stack before executing the SLEEP instruction if

Immediately after an interrupt is detected, the clock output on the CLKOUT pin may be unstable

until software standby mode is canceled.

STATUS0 pin goes high.

Canceling with Interrupt

Software Standby Mode

Transition to Software Standby Mode

Canceling Software Standby Mode

Rev. 1.00 Oct. 01, 2007 Page 679 of 1956

Section 18 Power-Down Mode

REJ09B0256-0100