Renesas H8/38024 Series, Hardware Manual

Page: 155 / 661

Rev. 6.00, 08/04, page 125 of 628
5.2.2 Clearing Sleep Mode
Sleep mode is cleared by any interrupt (timer A, timer C, timer F, timer G, asynchronous event
counter, IRQAEC, IRQ
4
, IRQ
3
, IRQ
1
, IRQ
0
, WKP
7
to WKP
0
, SCI3, A/D converter), or by input at
the
RES
pin.
•
Clearing by interrupt
When an interrupt is requested, sleep mode is cleared and interrupt exception handling starts.
A transition is made from sleep (high-speed) mode to active (high-speed) mode, or from sleep
(medium-speed) mode to active (medium-speed) mode. Sleep mode is not cleared if the I bit of
the condition code register (CCR) is set to 1 or the particular interrupt is disabled in the
interrupt enable register.
To synchronize the interrupt request signal with the system clock, up to 2/
φ
(s) delay may occur
after the interrupt request signal occurrence, before the interrupt exception handling start.
•
Clearing by
RES
input
When the
RES
pin goes low, the CPU goes into the reset state and sleep mode is cleared.
5.2.3 Clock Frequency in Sleep (Medium-Speed) Mode
Operation in sleep (medium-speed) mode is clocked at the frequency designated by the MA1 and
MA0 bits in SYSCR1.