SN32F760 Series
32-Bit Cortex-M0 Micro-Controller
SONiX TECHNOLOGY CO., LTD
Page 68
Version 2.0
4.4 WAKEUP
4.4.1
OVERVIEW
Under low power
mode, program doesn’t execute. The wakeup trigger can wake the system up to normal mode. The
wakeup function builds in interrupt operation and trigger system executing interrupt service routine as system wakeup
occurrence.
The wakeup trigger sources of the Sleep mode are all interrupts and the RESET pin.
The wakeup trigger sources of the Deep-sleep mode are the GPIO interrupt, RTC interrupt, LCD interrupt, and the
RESET pin.
The wakeup trigger sources of the Deep Power-down mode are DPDWAKEUP pins which are input pull-up and
latched before entering DPD mode.
4.4.2
WAKEUP TIME
When the system is in Sleep mode, the high clock is enabled or disabled by F/W. If the high clock stops and MCU is
waken up from Sleep mode, MCU waits for 2048 external high-speed oscillator clocks and 32 internal high-speed
oscillator clocks as the wakeup time to stable the oscillator circuit. After the wakeup time, the system goes into the
normal mode.
Note: Wakeup from Sleep mode spends NO wakeup time if
the clock doesn’t stop.
When the system is in Deep-sleep mode, the high clock will stop. When MCU is waken up from Deep-sleep mode,
MCU waits for 2T*ILRC and IHRC/EHS warm up time(32T*IHRC/2048T*EHS). After the wakeup time, the system goes
into the normal mode.
The value of the external high clock oscillator wakeup time from Deep sleep mode is as the following.
The total Wakeup time of EHS X
’tal = 2T*ILRC + 1/F
EHS
* 2048 (sec) + high clock start-up time
Example: F
EHS
=20MHz, the wakeup time from Deep sleep mode is as the following.
The total Wakeup time = 2T*ILRC + 1/F
EHS
* 2048 + oscillator start-up time
= 62.5us + 112.4 us + oscillator start-up time
(F
EHS
= 20MHz)
The value of the IHRC wakeup time is as the following.
The total Wakeup time of IHRC = 2T*ILRC + 1/F
IHRC
* 32 (sec)
Example: F
IHRC
=12MHz, the wakeup time is as the following.
The total Wakeup time = 2T*ILRC + 1/F
IHRC
* 32 = 62.5us + 2.67 us (F
IHRC
= 12MHz)