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HD6473032F16 Datasheet, PDF (640/847 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series
Section 19 Clock Pulse Generator
Table 19.1 (2) External Capacitance Values
External Capacitance Values
Frequency f (MHz)
CL1 = CL2 (pF)
5V operation
20 < f ≤ 25
10
2≤ f ≤ 20
10 to 22
3V operation
2≤ f ≤ 13
10 to 22
13≤ f ≤ 25
10
Crystal Resonator: Figure 19.3 shows an equivalent circuit of the crystal resonator. The crystal
resonator should have the characteristics listed in table 19.2.
XTAL
CL
L
Rs
EXTAL
C0
AT-cut parallel-resonance type
Figure 19.3 Crystal Resonator Equivalent Circuit
Table 19.2 Crystal Resonator Parameters
Frequency (MHz) 2
4
8
10
12
16
18
20
25
Rs max (Ω)
500 120 80
70
60
50
40
40
40
Co (pF)
7 pF
max
Use a crystal resonator with a frequency equal to the system clock frequency (φ).
Notes on Board Design: When a crystal resonator is connected, the following points should be
noted:
Other signal lines should be routed away from the oscillator circuit to prevent induction from
interfering with correct oscillation. See figure 19.4.
When the board is designed, the crystal resonator and its load capacitors should be placed as close
as possible to the XTAL and EXTAL pins.
Rev. 3.00 Mar 21, 2006 page 610 of 814
REJ09B0302-0300