SN8P1829
8-Bit MCU build-in 12-bit ADC + PGIA + Charge-pump Reg 128 dots LCD driver
SONiX TECHNOLOGY CO., LTD
Page 42
Version 1.0
7
7
7
OSCILLATORS
OVERVIEW
The SN8P1829 highly performs the dual clock micro-controller system. The dual clocks are high-speed clock and
low-speed clock. The high-speed clock frequency is supplied through the external oscillator circuit. The low-speed
clock frequency is supplied through external low clock oscillator (32.768K) by crystal or RC mode. Because
Real-Time-Clock (RTC) used low-speed clock for timer, 32768Hz X’tal usually used for low-speed clock to an
exact Real-Time-Clock
.
The external high-speed clock and the external low-speed clock can be system clock (F
OSC
). The system clock is
divided by 4 to be the instruction cycle (F
CPU
).
F
CPU
= F
OSC
/ 4
The system clock is required by the following peripheral modules:
Basic timer (T0)
Timer counter 0 (TC0)
Timer counter 1 (TC1)
Watchdog timer
Serial I/O interface (SIO)
AD converter
PWM output (PWM0OUT, PWM1OUT)
Buzzer output (TC0OUT, TC1OUT)
CLOCK BLOCK DIAGRAM
fl
CPUM0
LXOSC.
fcpu
fosc/4
CPUM0
fh
HXOSC.
XIN
XOUT
STPHX
HXRC
CPUM0
Divided by 4
CLKMD
Divided by 2
OSG
Divided by 2
1 : Disable
0 : Enable
OSG : Oscillator Safe Guard
1 : Disable -- System Default
0 : Enable
HXRC(1:0) is code option
•00= RC
•01 =32 Khz Oscillator
•10 = High Speed Oscillator (>10Mhz)
•11 = Standard Oscillator (4Mhz)
fl
CPUM0
LXOSC.
fl
CPUM0
LXOSC.
fcpu
fosc/4
CPUM0
fcpu
fosc/4
CPUM0
fh
HXOSC.
XIN
XOUT
STPHX
HXRC
CPUM0
fh
HXOSC.
XIN
XOUT
STPHX
HXRC
CPUM0
Divided by 4
CLKMD
Divided by 4
Divided by 4
CLKMD
Divided by 2
Divided by 2
OSG
OSG
Divided by 2
1 : Disable
0 : Enable
OSG : Oscillator Safe Guard
1 : Disable -- System Default
0 : Enable
HXRC(1:0) is code option
•00= RC
•01 =32 Khz Oscillator
•10 = High Speed Oscillator (>10Mhz)
•11 = Standard Oscillator (4Mhz)
Figure 7-1. Clock Block Diagram
HXOSC: External high-speed clock.
LXOSC: External low-speed clock.
OSG: Oscillator safe guard.