HD6417705 Datasheet, PDF (348/739 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH RISC engine Family/SH7700 Series

11.6.2 Canceling Module Standby Function
The module standby function can be canceled by clearing the MSTP bits to 0 or by a power-on
reset.
When canceling the module standby function by clearing the corresponding MSTP bit, be sure to
read the relevant MSTP bit to confirm that it has been cleared to 0.
11.7 Hardware Standby Mode
11.7.1 Transition to Hardware Standby Mode
The LSI enters hardware standby mode by driving the CA pin low. In hardware standby mode, as
the same as software standby mode entered by executing the SLEEP instruction, all modules halt
except ones operated by the RTC clock. Even in hardware standby mode, supply power to all
power supply pins including the RTC power supply pins.
As differing from software standby mode, an interrupt or manual reset cannot be accepted in
hardware standby mode.
When the CA pin is driven low, the LSI enters hardware standby mode in the following procedure
depending on the state of CPG.
During Software Standby Mode: The LSI enters the hardware standby state with the clock
halted. An interrupt or manual reset cannot be accepted.
During WDT Operation for Canceling Software Standby Mode by an Interrupt: The CPU
restarts the operation after software standby mode is canceled. Then, the LSI enters hardware
standby mode.
During Sleep Mode: The CPU restarts the operation after sleep mode is canceled. Then, the LSI
enters hardware standby mode.
In hardware standby mode, the CA pin must be held low.
11.7.2 Canceling Hardware Standby Mode
The hardware standby function can be canceled only by the power-on reset.
When the CA pin is driven high while the RESETP pin is low, the clock starts oscillating. Make
sure to hold the RESETP pin low until the oscillation stabilizes. Then, drive the RESETP pin high
to start the power-on resetting by the CPU.
The operation is not guaranteed when an interrupt or manual reset is input.
Rev. 2.00, 09/03, page 302 of 690