SN8P2318 Series
C-type LCD, RFC 8-Bit Micro-Controller
SONiX TECHNOLOGY CO., LTD
Page 57
Version 1.5
5.7 WAKEUP
5.7.1 OVERVIEW
Under power down mode (sleep mode) or green mode, program doesn
’t execute. The wakeup trigger can wake the
system up to normal mode or slow mode. The wakeup trigger sources are external trigger (P0/P1 level change) and
internal trigger (T0 timer overflow).
Power down mode is waked up to normal mode. The wakeup trigger is only external trigger (P0/P1 level change)
Green mode is waked up to last mode (normal mode or slow mode). The wakeup triggers are external trigger
(P0/P1 level change) and internal trigger (T0 timer overflow).
5.7.2 WAKEUP TIME
When the system is in power down mode (sleep mode), the high clock oscillator stops. When waked up from power
down mode, MCU waits a period for stabling the oscillator circuit. After the wakeup time, the system goes into the
normal mode.
Note: Wakeup from green mode is no wakeup time because the clock
doesn’t stop in green mode.
The wake-up time of the external high-speed (12M_X
’tal, 4M_C’tal) crystal type oscillator is as the following.
The Wakeup time = 1/Fhosc * 2560 (sec) + high clock start-up time
Example: In power down mode (sleep mode), the system is waked up. After the wakeup time, the system
goes into normal mode. The wakeup time is as the following.
The wakeup time = 1/Fhosc * 2560 = 0.64 ms (4MHz crystal)
The total wakeup time = 0.64 ms + oscillator start-up time
The wake-up time of the external high/low speed RC type oscillator is as the following.
The Wakeup time = 1/Fosc * 32 (sec) + clock start-up time
Example: In power down mode (sleep mode), the system is waked up. After the wakeup time, the system
goes into normal mode. The wakeup time is as the following.
The wakeup time = 1/Fhosc * 32 = 8 us (4MHz RC)
The total wakeup time = 8 us + oscillator start-up time
The wakeup time = 1/Fhosc * 32 = 1 ms (32KHz RC)
The total wakeup time = 1 ms + oscillator start-up time
The wake-up time of the external low-speed crystal type oscillator is as the following.
The Wakeup time (32K_X
’tal) = 1/Flosc * (2
14
+256) + low clock start-up time