SH7052 Datasheet, PDF (817/919 Pages) Renesas Technology Corp – SuperHTM RISC engine

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
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