SH7052 datasheet(817/919 Pages) RENESAS

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Section 23 Power-Down State

23.1

Overview

Three modes are provided as power-save modes, namely, the hardware standby, software standby

and sleep modes. Also, a module stop function is available to stop some modules. These standby

modes can be selected depending on applications to reduce the power consumption of the

SH7052F/SH7053F/SH7054F.

23.1.1

Power-Down States

The power-down state is effected by the following modes:

1. Hardware standby mode

A transition to hardware standby mode is made according to the input level of the

RES and

HSTBY pins.

In hardware standby mode, all SH7052F/SH7053F/SH7054F functions are halted.

This state is exited by means of a power-on reset.

2. Software standby mode

A transition to software standby mode is made by means of software (a CPU instruction).

In software standby mode, all SH7052F/SH7053F/SH7054F functions are halted.

This state is exited by means of a power-on reset or an NMI interrupt.

3. Sleep mode

A transition to sleep mode is made by means of a CPU instruction.

In software standby mode, basically only the CPU is halted, and all on-chip peripheral modules

operate.

This state is exited by means of a power-on reset, a manual reset, interrupt, or DMA address

error.

4. Module standby mode

Operation of the on-chip peripheral modules* which can be placed in a standby mode can be

stopped by stopping the clock supply. Clock supply to the individual modules can be

controlled by setting bits in the module standby control register (MSTCR).

Note: * AUD, H-UDI, and UBC

SH7052 Datasheet(PDF) 817 Page - Renesas Technology Corp