Datasheet

Section 5 Clock Pulse Generator
Rev. 3.00 Sep. 10, 2007 Page 89 of 528
REJ09B0216-0300
C
S
C
O
R
S
L
S
PC0/OSC1 PC1/OSC2/CLKOUT
Figure 5.13 Equivalent Circuit of Crystal Resonator
Table 5.1 Crystal Resonator Parameters
Frequency (MHz) 4 8 10 16 20
R
S
(Max.) 120 Ω 80 Ω 60 Ω 50 Ω 40 Ω
C
O
(Max.) 70 pF
5.5.2 Connecting Ceramic Resonator
Figure 5.14 shows an example of connecting a ceramic resonator.
C
1
C
2
PC0/OSC1
PC1/OSC2/CLKOUT
C = C = 5 to 30 pF
1 2
Figure 5.14 Example of Connection to Ceramic Resonator
5.5.3 Inputting External Clock
To use the external clock, input the external clock on pin OSC1. Figure 5.15 shows an example of
connection. The duty cycle of the external clock signal must range from 45 to 55%.
PC0/OSC1
PC1/OSC2/CLKOUT
External clock input
Open
Figure 5.15 Example of External Clock Input