SN8P1829
8-Bit MCU build-in 12-bit ADC + PGIA + Charge-pump Reg 128 dots LCD driver
SONiX TECHNOLOGY CO., LTD
Page 48
Version 1.0
SYSTEM MODE DESCRIPTION
OVERVIEW
The chip is featured with low power consumption by switching around three different modes as following.
High-speed mode
Low-speed mode
Power-down mode (Sleep mode)
Green mode
In actual application, the user can adjust the chip’s controller to work in these four modes by using OSCM register. At
the high-speed mode, the instruction cycle (F
CPU
) is Fosc/4. At the low-speed mode and 3V, the F
CPU
is 16KHz/4.
NORMAL MODE
In normal mode, the system clock source is external high-speed clock. After power on, the system works under normal
mode. The instruction cycle is fosc/4. When the external high-speed oscillator is 3.58MHz, the instruction cycle is
3.58MHz/4 = 895KHz. All software and hardware are executed and working. In normal mode, system can get into
power down mode, slow mode and green mode.
SLOW MODE
In slow mode, the system clock source is external low-speed RC clock. To set CLKMD = 1, the system switches into
slow mode. In slow mode, the system works as normal mode but the clock slower. The system in slow mode can get
into normal mode, power down mode and green mode. To set STPHX = 1 to stop the external high-speed oscillator,
and then the system consumes less power.
GREEN MODE
The green mode is a less power consumption mode. Under green mode, there are only T0 still counting and the other
hardware stopping. The external high-speed oscillator or external low-speed oscillator is operating. To set CPUM1 = 1
and CPUM0 = 0, the system gets into green mode. The system can be waked up to last system mode by T0 timer
timeout and P0, P1 trigger signal.
The green mode provides a time-variable wakeup function. Users can decide wakeup time by setting T0 timer. There
are two channels into green mode. One is normal mode and the other is slow mode. In normal mode, the T0 timers
overflow time is very short. In slow mode, the overflow time is longer. Users can select appropriate situation for their
applications. Under green mode, the power consumption is 5u amp in 3V condition.
SLEEP (POWER DOWN) MODE
The power down mode is also called sleep mode. The chip stops working as sleeping status. The power consumption
is very less almost to zero. The power down mode is usually applied to low power consuming system as battery power
productions. To set CUPM0 = 1, the system gets into power down mode. The external high-speed and low-speed
oscillators are turned off. The system can be waked up by P0, P1 trigger signal.
