171
Clock Generator
Chapter 4
Preliminary User’s Manual U17566EE1V2UM00
(3)
WATCH mode
In WATCH mode, the clock supply for the CPU system and the majority of
peripherals is stopped.
The main oscillator continues operation. PLL and SSCG are stopped. By
default, ring oscillator and sub oscillator operation is not affected. For
exceptions see
“Ring and sub oscillator operation” on page 184
.
The WATCH mode can be released by
• the unmasked maskable interrupts INTPn, INTCnWUP, INTWTnUV,
INTTM01, INTVCn, INTCBnR
• NMI0, NMIWDT
• RESET, RESPOC, RESWDT, RESCMM, RESCMS
On WATCH mode release, the CPU starts operation using the following
clocks:
• if PSM.OSCDIS = 1: sub clock source selected before WATCH mode was
entered, that means, either ring oscillator or sub oscillator (defined by
PCC.SOSCP)
• if PSM.OSCDIS = 0: main oscillator
If the ring oscillator was stopped before entering the WATCH mode, the
oscillation stabilization time for the ring oscillator is ensured by hardware after
WATCH mode release.
PLL and SSCG remain stopped after WATCH release.
Peripheral clock supply is switched to main oscillator supply, if
PSM.OSCDIS = 0, otherwise the ring oscillator is used for peripheral clocks.
Table 4-26
Clock Generator status in WATCH mode
Item
Status
Remarks
Main oscillator
unchanged/stopped
Stopped if PSM.OSCDIS = 1
Sub oscillator
operates
Ring oscillator
operates/stopped
Stopped if WCC.ROSTP = 1
SSCG
stopped
PLL
stopped
VBCLK (CPU system)
stopped
IICLK
stopped
PCLK0, PCLK1
stopped
PCLK2…PCLK15
stopped
SPCLK0, SPCLK1
stopped
SPCLK2…SPCLK15
stopped
FOUTCLK
unchanged/stopped
Stopped, if the selected clock
source stops
WTCLK / LCDCLK
unchanged/stopped
Stopped, if the selected clock
source stops
WDTCLK
unchanged/stopped
Stopped, if the selected clock
source stops
WCTCLK
unchanged/stopped
Depends on clock selector
PSM.CMODE
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