SN8P2200 Series
USB 1.1 Low-Speed 8-Bit Micro-Controller
SONiX TECHNOLOGY CO., LTD
Page 51
Version 1.7
4.4
SYSTEM HIGH CLOCK
The system high clock is from internal 6MHz oscillator RC type or external oscillator. The high clock type is controlled
by “High_Clk” code option.
High_Clk Code Option
Description
IHRC_6M
The high clock is internal 6MHz oscillator RC type. XIN and XOUT pins are general
purpose I/O pins.
IHRC_RTC
The high clock is internal 6MHz oscillator RC type. XIN and XOUT pins connect with
32768Hz crystal for RTC clock source.
6M
The high clock is external oscillator and only for 6MHz.
4.4.1 INTERNAL HIGH RC
The chip is built-in RC type internal high clock (6MHz) controlled by “IHRC_6M” or “IHRC_RTC” code options. In
“IHRC_6M” mode, the system clock is from internal 6MHz RC type oscillator and XIN / XOUT pins are general-purpose
I/O pins. In “IHRC_RTC” mode, the system clock is from internal 6MHz RC type oscillator and XIN / XOUT pins are
connected with external 32768 crystal for real time clock (RTC).
z
IHRC:
High clock is internal 6MHz oscillator RC type. XIN/XOUT pins are general purpose I/O pins.
z
IHRC_RTC:
High clock is internal 6MHz oscillator RC type. XIN/XOUT pins are connected with external 32768Hz
crystal/ceramic oscillator for RTC clock source.
The RTC period is 0.5 sec and RTC timer is T0. Please consult “T0 Timer” chapter to apply RTC function.
4.4.2 EXTERNAL HIGH CLOCK
External high clock is only support 6MHz Crystal/Ceramic. The high clock oscillator module is controlled by High_Clk
code option.
4.4.2.1
CRYSTAL/CERAMIC
Crystal/Ceramic devices are driven by XIN, XOUT pins. 6M option is for high speed 6MHz. In IHRC_RTC mode,
XIN/XOUT is connected with 32768Hz crystal for 0.5 sec RTC.
MCU
VCC
GND
C
20pF
XIN
XOUT
VDD
VSS
C
20pF
CRYSTAL
Note: Connect the Crystal/Ceramic and C as near as possible to the XIN/XOUT/VSS pins of
micro-controller.