h8s-2649 Renesas Electronics Corporation., h8s-2649 Datasheet - Page 600

• Manufacturer Part Number: h8s-2649
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

Section 20 Clock Pulse Generator
20.2
Clock pulses can be supplied by connecting a crystal resonator, or by input of an external clock. In
either case, the input clock should not exceed 20 MHz.
20.2.1
Circuit Configuration: A crystal resonator can be connected as shown in the example in figure
20.2. Select the damping resistance R
crystal should be used.
Table 20.1 Damping Resistance Value
Figure 20.3 shows the equivalent circuit of the crystal resonator. Use a crystal resonator that has
the characteristics shown in table 20.2.
Rev. 2.00 Dec. 05, 2005 Page 562 of 724
REJ09B0200-0200
Frequency (MHz)
R
d
(Ω)
Oscillator
Connecting a Crystal Resonator
Figure 20.2 Connection of Crystal Resonator (Example)
EXTAL
XTAL
XTAL
Figure 20.3 Crystal Resonator Equivalent Circuit
4
500
R
d
L
d
according to table 20.1. An AT-cut parallel-resonance
8
200
C
C
C
C
L1
L2
L
0
AT-cut parallel-resonance type
R
s
10
0
C
L1
EXTAL
= C
L2
12
0
= 10 to 22 pF
16
0
20
0