HD6412240 RENESAS [Renesas Technology Corp], HD6412240 Datasheet - Page 589

• Manufacturer Part Number: HD6412240
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family / H8S/2200 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

Crystal resonator
Figure 17.3 shows the equivalent circuit of the crystal resonator. Use a crystal resonator that has
the characteristics shown in table 17.3 and the same resonance frequency as the system clock ( ).
Table 17.3 Crystal Resonator Parameters
Note 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 17.4.
When designing the board, place the crystal resonator and its load capacitors as close as possible
to the XTAL and EXTAL pins.
Frequency (MHz)
R
C
s
0
max ( )
max (pF)
XTAL
Figure 17.3 Crystal Resonator Equivalent Circuit
Figure 17.4 Example of Incorrect Board Design
Avoid
2
500
7
C
C
L2
L1
L
Signal A Signal B
4
120
7
C
C
L
0
AT-cut parallel-resonance type
R
s
8
80
7
Rev.3.00 Mar. 26, 2007 Page 547 of 772
XTAL
EXTAL
H8S/2245
EXTAL
Section 17 Clock Pulse Generator
12
60
7
16
50
7
REJ09B0355-0300
20
40
7