hd66100 Renesas Electronics Corporation., hd66100 Datasheet - Page 122

• Manufacturer Part Number: hd66100
• Description: H8/3867 Series
• Manufacturer: Renesas Electronics Corporation.

5.4
5.4.1
The system goes from active or subactive mode to watch mode when a SLEEP instruction is
executed while the SSBY bit in SYSCR1 is set to 1 and bit TMA3 in TMA is set to 1.
In watch mode, operation of on-chip peripheral modules is halted except for timer A, timer F,
timer G, AEC and the LCD controller/driver (for which operation or halting can be set) is halted.
As long as a minimum required voltage is applied, the contents of CPU registers, the on-chip
RAM and some registers of the on-chip peripheral modules, are retained. I/O ports keep the same
states as before the transition.
5.4.2
Watch mode is cleared by an interrupt (timer A, timer F, timer G, IRQ
input at the RES pin.
• Clearing by interrupt
When watch mode is cleared by interrupt, the mode to which a transition is made depends on the
settings of LSON in SYSCR1 and MSON in SYSCR2. If both LSON and MSON are cleared to 0,
transition is to active (high-speed) mode; if LSON = 0 and MSON = 1, transition is to active
(medium-speed) mode; if LSON = 1, transition is to subactive mode. When the transition is to
active mode, after the time set in SYSCR1 bits STS2 to STS0 has elapsed, a stable clock signal is
supplied to the entire chip, watch mode is cleared, and interrupt exception handling starts. Watch
mode is not cleared if the I bit of CCR is set to 1 or the particular interrupt is disabled in the
interrupt enable register.
• Clearing by RES input
Clearing by RES pin is the same as for standby mode; see 2. Clearing by RES pin in 5.3.2,
Clearing Standby Mode.
5.4.3
The waiting time is the same as for standby mode; see 5.3.3, Oscillator Settling Time after
Standby Mode is Cleared.
Watch Mode
Transition to Watch Mode
Clearing Watch Mode
Oscillator Settling Time after Watch Mode is Cleared
0
, or WKP
7
to WKP
0
) or by
107