System Clock Generator - Renesas H8 Series Hardware Manual

Section 4 Clock Pulse Generators
4.2

System Clock Generator

Clock pulses can be supplied to the system clock divider either by connecting a crystal or ceramic
resonator, or by providing external clock input.
Connecting a Crystal Resonator: Figure 4.2 shows a typical method of connecting a crystal
resonator.
Figure 4.2 Typical Connection to Crystal Resonator
Figure 4.3 shows the equivalent circuit of a crystal resonator. An oscillator having the
characteristics given in table 4.1 should be used.
OSC
1
Table 4.1 Crystal Resonator Parameters
Frequency
R (max)
S
C (max)
0
Rev. 6.00 Sep 12, 2006 page 82 of 526
REJ09B0326-0600
OSC
1
R
f
OSC
2
C
L
S
Figure 4.3 Equivalent Circuit of Crystal Resonator
2 MHz
500 Ω
7 pF
C
1
R = 1 M
f
C = C = 12 pF ±20%
1 2
C
2
S
R
S
C
0
4 MHz 8 MHz
100 Ω 50 Ω
7 pF 7 pF
Ω
±20%
OSC
10 MHz
30 Ω
7 pF
2