GMS81C50 Datasheet, PDF (77/99 Pages) Hynix Semiconductor – 8-BIT SINGLE CHIP MICROCONTROLLERS

GMS81C50 Series
HYUNDAI
15. OSCILLATION CIRCUIT
Oscillation circuit is designed to be used either with a ce-
ramic resonator or crystal oscillator. Fig. 4.2-(a) shows
circuit diagrams using a crystal (or ceramic) oscillator. As
shown in the diagram, oscillation circuits can be construct-
ed by connecting a oscillator between Xout and Xin.
Clock from oscillation circuit makes CPU clock via clock
pulse generator, and then enters prescaler to make periph-
eral hardware clock. Alternately, the oscillator may be
driven from an external source as shown is Fig. 4.2.-(b). In
the Standby (STOP) mode, oscillatiion stop, Xout state
goes to ``HIigh``, Xin state goes to ``Low``, and built-in
feed back resistor is disabled.
(a) External Crystal (Ceramic) oscillator circuit
Cout
Xout
Xin
Cin
(b) External clock input circuit
Xout
Xin
External clock
Figure 15-1 Oscillator configurations
* Recommendable resonator
Frequency
4.0 MHz
Resonator Maker
CQ
TDK
TDK
TDK
Part Name
ZTA4.00MG
FCR4.0MC5
FCR4.0M5
CCR4.0MC3
Load Capacitor
Cin=Cout=30pF
Cin=Cout=open
Cin=Cout=33pF
Operating Voltage
2.2 ~ 4.0V
2.2 ~ 4.0V
2.2 ~ 4.0V
2.2 ~ 4.0V
* MC type is building in load capacitior.CCR type is chip type.
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