SH7720 Datasheet, PDF (552/1524 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7700 Series

Section 13 Power-Down Modes
Immediately after an interrupt is detected, the phase of the clock output of the CKIO pin may be
unstable, until software standby mode is canceled.
Notes: 1. Only when the RTC is used, software standby mode can be canceled by IRQ (edge
detection), RTC, TMU, or PINT interrupt.
2. Cancel this software standby mode by a power-on reset.
WTCNT value
Interrupt
request
Crystal oscillator settling
time and PLL synchronization
time
WDT overflow and branch to
interrupt handling routine
Clear the STBY bit in STBCR before
WTCNT reaches H'80. When
he STBY bit in STBCR is cleared,
WTCNT halts automatically.
H'FF
H'80
Time
Figure 13.1 Canceling Standby Mode with STBY Bit in STBCR
(2) Canceling with Reset
Software standby mode is canceled by a reset with the RESETP pin and RESETM pin. Keep the
RESETP pin and RESETM pin low until the clock oscillation settles in clock operating mode to
use PLL. The internal clock will continue to be output to the CKIO pin.
Rev. 3.00 Jan. 18, 2008 Page 490 of 1458
REJ09B0033-0300