Datasheet

Section 5 Clock Pulse Generators
Rev. 3.00 Sep. 14, 2006 Page 82 of 408
REJ09B0105-0300
5.5 External Oscillators
This LSI has two methods to supply external clock pulses into it: connecting a crystal or ceramic
resonator, and an external clock. Oscillation pins OSC1 and OSC2 are common with general ports
PC0 and PC1, respectively. To set pins PC0 and PC1 as crystal resonator or external clock input
ports, refer to section 5.3, System Clock Select Operation.
5.5.1 Connecting Crystal Resonator
Figure 5.9 shows an example of connecting a crystal resonator. An AT-cut parallel-resonance
crystal resonator should be used. Figure 5.12 shows the equivalent circuit of a crystal resonator. A
resonator having the characteristics given in table 5.1 should be used.
C
1
C
2
PC0/OSC1
PC1/OSC2/CLKOUT
C = C = 10 to 22 pF
1 2
Figure 5.9 Example of Connection to Crystal Resonator
C
S
C
0
R
S
L
S
PC0/OSC1 PC1/OSC2/CLKOUT
Figure 5.10 Equivalent Circuit of Crystal Resonator
Table 5.1 Crystal Resonator Parameters
Frequency (MHz) 2 4 8 10 12
R
S
(Max.) 500 Ω 120 Ω 80 Ω 60 Ω 50 Ω
C
0
(Max.) 70 pF