SN8P2318 Series
C-type LCD, RFC 8-Bit Micro-Controller
SONiX TECHNOLOGY CO., LTD
Page 47
Version 1.5
4.3.1 HIGH_CLK CODE OPTION
For difference clock functions, Sonix provides multi-type system high clock options controlled by
“High_Clk” code
option. The High_Clk code option defines the system oscillator types including PLL_16M, RC, 12M X
’tal and 4M X’tal.
These oscillator options support different bandwidth oscillator.
PLL_16M:
The system high-speed clock source is internal PLL high-speed 16MHz type oscillator. The PLL is
pumped from external 32KHz low-speed oscillator (LXINT/XOUT).
RC:
The system high-speed clock source is external low cost RC type oscillator. The RC oscillator circuit only
connects to XIN pin, and the XOUT pin is Fcpu signal output.
12M X
’tal:
The system high-speed clock source is external high-speed crystal/ceramic. The oscillator bandwidth
is 10MHz~16MHz.
4M X
’tal:
The system high-speed clock source is external high-speed crystal/resonator. The oscillator bandwidth
is 1MHz~10MHz.
4.3.2 INTERNAL HIGH-SPEED OSCILLATOR
The internal high-speed oscillator is 16MHz PLL type. The accuracy is
±
2% under commercial condition. When the
“High_Clk” code option is “PLL_16M”, the internal high-speed oscillator is enabled.
PLL_16M:
The system high-speed clock is internal 16MHz oscillator RC type. LXIN/LXOUT pins connects
external low-speed 32KHz oscillator. XIN pin connects a 0.1uF decouple capacitor to VDD. XOUT pin is GPIO
structure.
INTERNAL HIGH-SPEED OSCILLATOR APPLICATION CIRCUIT
MCU
VCC
GND
XIN
VSS
V
D
D
C
0.1uF
LXIN
LXOUT
32KHz Oscillator
Circuit
4.3.3 EXTERNAL HIGH-SPEED OSCILLATOR
The external high-speed oscillator includes 4MHz, 12MHz and RC type controlled by
“High_Clk” code option. The
4MHz and 12MHz oscillators support crystal and ceramic types connected to XIN/XOUT pins with 20pF capacitors to
ground. The RC type is a low cost RC circuit only connected to XIN pin. The capacitance is not below 100pF, and use
the resistance to decide the frequency.
EXTERNAL OSCILLATOR APPLICATION CIRCUIT
CRYSTAL/CERAMIC:
RC Type:
MCU
VCC
GND
C
20pF
XIN
XOUT
VDD
V
S
S
C
20pF
CRYSTAL
R
MCU
VCC
GND
XIN
XOUT
VDD
VSS
C