HMS81008E Hynix Semiconductor, HMS81008E Datasheet - Page 37

• Manufacturer Part Number: HMS81008E
• Description: HYNIX SEMICONDUCTOR 8-BIT SINGLE-CHIP MICROCONTROLLERS
• Manufacturer: Hynix Semiconductor

HMS81004E/08E/16E/24E/32E
10.1 Oscillation Circuit
Oscillation circuit is designed to be used either with a ce-
ramic resonator or crystal oscillator. Figure 10-2 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. Colck
from oscillation circuit makesCPU clock via clock pulse
generator, and then enters prescaler to make peripheral
hardware clock. Alternately, the oscillator may be driven
from an esternal source as Figure 10-3 . In the STOP
mode,oscillation stop, Xout state goes to “HIGH” , Xin
state goes to “LOW” , and built-in feed back resistor is dis-
abled.
34
Figure 10-2 External Crystal(Ceramic) oscillator circuit
External
Clock
Source
Figure 10-3 External clock input circuit
Cout
Cin
OPEN
Xout
Xin
Vss
Xout
Xin
Vss
Oscillation circuit is designed to be used either with a ce-
ramic resonator or crystal oscillator. Since each crystal and
ceramic resonator have their own characteristics, the user
should consult the crystal manufacturer for appropriate
values of external components. In addition, see Figure 10-
4 for the layout of the crystal.
Note: Minimize the wiring length. Do not allow the wiring to
intersect with other signal conductors. Do not allow the wir-
ing to come near changing high current. Set the potential of
the grounding position of the oscillator capacitor to that of
V
rent is present. Do not fetch signals from the oscillator.
SS
Figure 10-4 Recommend Layout of Oscillator PCB
. Do not ground it to any ground pattern where high cur-
X
X
OUT
IN
circuit
JUNE 2001 Ver 1.00