h8s-2646 Renesas Electronics Corporation., h8s-2646 Datasheet - Page 785

• Manufacturer Part Number: h8s-2646
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

22.6.2
Software standby mode is cleared by an external interrupt (NMI pin, or pins IRQ0 to IRQ5), or by
means of the RES pin or STBY pin.
• Clearing with an interrupt
• Clearing with the RES pin
• Clearing with the STBY pin
When an NMI or IRQ0 to IRQ5 interrupt request signal is input, clock oscillation starts, and
after the elapse of the time set in bits STS2 to STS0 in SYSCR, stable clocks are supplied to
the entire H8S/2646 Group chip, software standby mode is cleared, and interrupt exception
handling is started.
When clearing software standby mode with an IRQ0 to IRQ5 interrupt, set the corresponding
enable bit to 1 and ensure that no interrupt with a higher priority than interrupts IRQ0 to IRQ5
is generated. Software standby mode cannot be cleared if the interrupt has been masked on the
CPU side or has been designated as a DTC activation source.
When the RES pin is driven low, clock oscillation is started. At the same time as clock
oscillation starts, clocks are supplied to the entire H8S/2646 Group chip. Note that the RES
pin must be held low until clock oscillation stabilizes. When the RES pin goes high, the CPU
begins reset exception handling.
When the STBY pin is driven low, a transition is made to hardware standby mode.
Clearing Software Standby Mode
Rev. 5.00 Sep 22, 2005 page 759 of 1136
Section 22 Power-Down Modes
REJ09B0257-0500