Datasheet

Section 5 Clock Pulse Generators
Rev. 1.50 Sep. 18, 2007 Page 84 of 584
REJ09B0240-0150
5.5 External Oscillator
This LSI has two methods to supply external clock pulses into it: connecting a crystal or ceramic
resonator, and an external clock. Oscillation pins PJ0/OSC1 and PJ1/OSC2/CLKOUT 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 5.3.2, Clock Control Operation.
LPM
LPM: Power-down mode (standby mode, subactive mode, or subsleep mode)
OSC2
OSC1
Figure 5.9 Block Diagram of External Oscillator
5.5.1 Connecting Crystal Resonator
Figure 5.10 shows an example of connecting a crystal resonator. An AT-cut parallel-resonance
crystal resonator should be used. Figure 5.11 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
OSC1
OSC2
C
1
= C
2
= 12 pF ±20%
Figure 5.10 Example of Connection to Crystal Resonator
C
S
C
O
R
S
L
S
OSC1 OSC2
Figure 5.11 Equivalent Circuit of Crystal Resonator