204
8.7.2
Canceling Hardware Standby Mode
Hardware standby mode can only be canceled by a power-on reset.
When the CA pin is driven high while the
RESETP
pin is low, clock oscillation is started. Hold
the
RESETP
pin low until clock oscillation stabilizes. When the
RESETP
pin is driven high, the
CPU begins power-on reset processing.
Operation is not guaranteed in the event of an interrupt or manual reset.
8.7.3
Hardware Standby Mode Timing
Figures 8.10 and 8.11 show examples of pin timing in hardware standby mode.
The CA pin is sampled using EXTAL2 (32.768 kHz), and a hardware standby request is only
recognized when the pin is low for two consecutive clock cycles.
The CA pin must be held low while the chip is in hardware standby mode.
Clock oscillation starts when the CA pin is driven high after the
RESETP
pin is driven low.
Summary of Contents for SH7709S
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