HE84760 Datasheet, PDF (15/31 Pages) King blillion Electronics Co.,Ltd. – 8-bit Micro-controller

King Billion Electronics Co., Ltd
駿億電子股份有限公司
HE84760
HE80000 SERIES
FXI
FXI
22p
R
3579545Hz
22p
FXO
Crystal Osc.
RC Osc.
The RC oscillator has a built-in capacitor. An external resistor is needed to connect from FXI to GND to
determine the oscillation frequency. The capacitance of internal RC oscillator is selected by mask option
MO_RCAP[2..0].
MO_RCAP[2..0] Internal RC Cap. OSC. (pF)
000
2
001
4
010
7
011
14
100
20
101
40
110
50
111
60
The following table shows the combinations of R and C, and the resulting frequency. Please note that
oscillation frequency in the table only represents oscillation frequencies of certain samples. The actual
oscillation frequency may vary up to ±15% from lot to lot due to process parameter variations. User must
take this into consideration when using this chip in applications.
Ring Oscillator Frequency Table
R(K ohm )\C (pF) 40 20 14 7 4 2
30.20
0.8 1.5 2.0 3.0 4.0 5.0 MHz
19.92
1.2 2.2 2.8 4.4 5.6 7.0 MHz
9.98
2.3 4.0 5.1 7.5 9.4 11.4 MHz
Two types of oscillator, crystal and RC, can be used as slow clock by mask option MO_SXTAL. If used
for time keeping function or other applications that required the accurate timing, crystal oscillator is
recommended. If the timing accuracy is not important, then RC type oscillator can be used to reduce cost.
MO_SXTAL
Slow Clock Type
0
R/C oscillator
1
Crystal oscillator
August 15, 2003
Page 15 of 31
V1.2
This specification is subject to change without notice. Please contact sales person for the latest version before use.