SN32F280 Series
32-Bit Cortex-M0 Micro-Controller
SONiX TECHNOLOGY CO., LTD
Page 57
Version 1.1
3.2.3 EXTERNAL CLOCK SOURCE
3.2.3.1
External High-speed (EHS) Clock
External high clock includes Crystal/Ceramic modules. The startup time of Crystal is longer. The oscillator start-up time
decides reset time length.
3.2.3.2
CRYSTAL/CERAMIC
Crystal/Ceramic devices are driven by XIN, XOUT pins. For high/normal/low frequency, the driving currents are
different.
MCU
VCC
GND
C
20pF
XIN
XOUT
VDD
V
S
S
C
20pF
CRYSTAL
Note: Connect the Crystal/Ceramic and C as near as possible to the XIN/XOUT/VSS pins of MCU.
Structure:
10MHz~25MHz EHS external crystal/ceramic resonator
Main Purpose:
System high clock source, RTC clock source, and PLL clock source.
Warm-up Time:
2048*F
EHS
XIN/XOUT Shared Pin Selection:
Oscillator Mode
XIN pin
XOUT pin
IHRC
GPIO
GPIO
EHS X’TAL
Crystal/Ceramic
Crystal/Ceramic
4MHz Ceramic
4MHz Crystal