Section 22 Power-Down Modes
Rev. 5.00 May 29, 2006 page 575 of 698
REJ09B0146-0500
Canceling with an Interrupt: The on-chip WDT can be used for hot starts. When the chip detects
an NMI, IRL*
1
, IRQ*
1
, or on-chip supporting module (except the interval timer)*
2
interrupt, the
clock will be supplied to the entire chip and software standby mode canceled after the time set in
the WDT's timer control/status register has elapsed. The STATUS1 and STATUS0 pins both go
low. Interrupt processing then begins and a code indicating the interrupt source is set in the
INTEVT and INTEVT2 registers. After branching to the interrupt processing routine occurs, clear
the STBY bit in the STBCR register. The WTCNT stops automatically. If the STBY bit is not
cleared, WTCNT continues operation and transits to the standby mode*
3
when it reaches H'80.
This function prevents the data from being destroyed due to a rising voltage under an unstable
power supply. Interrupts are accepted during software standby mode even when the BL bit in the
SR register is 1. If necessary, save SPC and SSR in the stack before executing the SLEEP
instruction. Immediately after an interrupt is detected, the phase of the clock output of the CKIO
pin may be unstable, until the processor starts interrupt processing. (The canceling condition is
that the
IRL3
to
IRL0
level is higher than the mask level in the I3 to I0 bits in the SR register.)
Notes: 1. Software Standby mode can be canceled using
IRL3
to
IRL0
or IRQ4 to IRQ0.
2. Software standby mode can be canceled with an RTC or TMU (only when running on
the RTC clock) interrupt.
3. Standby mode should be canceled by power-on resets. Operations at manual resets or
during interrupt input are not guaranted.
WTCNT value
H'FF
H'80
Time
Interrupt
request
WDT overflow and branch to
interrupt handling routine
Crystal oscillator settling
time and PLL synchronization
time
Clear bit STBCR.STBY before
WTCNT reaches H'80. When
STBCR.STBY is cleared, WTCNT
halts automatically.
Figure 22.1 Canceling Software Standby Mode with STBCR.STBY
Canceling with a Reset: Standby mode can be canceled with a reset (power-on or manual). Keep
the
RESETP
pin and
RESETM
pin low until the clock oscillation settles.
Summary of Contents for SH7706 Series
Page 8: ...Rev 5 00 May 29 2006 page viii of xlviii ...
Page 160: ...Section 5 Cache Rev 5 00 May 29 2006 page 112 of 698 REJ09B0146 0500 ...
Page 370: ...Section 11 Watchdog Timer WDT Rev 5 00 May 29 2006 page 322 of 698 REJ09B0146 0500 ...
Page 554: ...Section 17 Pin Function Controller PFC Rev 5 00 May 29 2006 page 506 of 698 REJ09B0146 0500 ...
Page 576: ...Section 18 I O Ports Rev 5 00 May 29 2006 page 528 of 698 REJ09B0146 0500 ...
Page 746: ...Index Rev 5 00 May 29 2006 page 698 of 698 REJ09B0146 0500 ...
Page 749: ...SH7706 Group Hardware Manual ...