SH7763 Datasheet, PDF (1894/2026 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC Engine Family SH-4A Series

Section 43 Electrical Characteristics
43.2.3 Power-Off and Power-On Order in RTC Power-Supply Backup Mode (Hardware
Standby)
To use RTC power supply backup mode, the RTC clock should be supplied.
First bring the XRTCSTBI pin low, and then make sure that the STATUS0 and STATUS1 pins
have been pulled high and low, respectively. After that, turn off the power supplies (VCCQ,
AVCC), (VCCQ-DDR), and (VDD, VDD-PLL1 to 3, VDD-DLL1 to 3). The power supply VDD-
RTC should remain on, and the XRTCSTBI pin should remain low.
Turn on the power supplies (VCCQ, AVCC), (VCCQ-DDR), and (VDD, VDD-PLL1 to 3, VDD-
DLL1 to 3) while the XRTCSTBI pin is low. After these power supplies become stable, bring the
XRTCSTBI pin high and negate the PRESET pin to high level.
43.2.4 Power-Off and Power-On Order in DDR-SDRAM Power-Supply Backup Mode
To use DDR-SDRAM power-supply backup mode, the DDR-SDRAM should be placed in the
self-refresh state. After the DDR-SDRAM is placed in the self-refresh state, bring the M-CKE pin
low. Make sure that the SELFS bit in the MIM register is set to 1, and then bring the M_BKPRST
pin low. After that, turn off the power supplies (VCCQ, AVCC, VDD-RTC) and (VDD, VDD-
PLL1 to 3, VDD-DLL1 to 3). The power supply VCCQ-DDR should remain on and the
M_BKPRST pin should remain low.
Turn on the power supplies (VCCQ, AVCC, VDD-RTC) and (VDD, VDD-PLL1 to 3, VDD-
DLL1 to 3) while the M_BKPRST pin is low. After these power supplies become stable, negate
the M_BKPRST and PRESET pins to high level.
Rev. 1.00 Oct. 01, 2007 Page 1828 of 1956
REJ09B0256-0100