Oscillator; Connecting A Crystal Resonator - Renesas H8S/2319 series Hardware Manual

Bit 2 Bit 1 Bit 0
SCK2 SCK1 SCK0
0 0 0
1
1 0
1
1 0 0
1
1 —
18.3

Oscillator

Clock pulses can be supplied by connecting a crystal resonator, or by input of an external clock.
18.3.1

Connecting a Crystal Resonator

Circuit Configuration: A crystal resonator can be connected as shown in the example in figure
18-2. Select the damping resistance R
crystal should be used.
EXTAL
XTAL
Figure 18-2 Connection of Crystal Resonator (Example)
Table 18-2 Damping Resistance Value
Frequency (MHz)
(Ω Ω Ω Ω )
R
d
Crystal Resonator: Figure 18-3 shows the equivalent circuit of the crystal resonator. Use a
crystal resonator that has the characteristics shown in table 18-3 and the same resonance frequency
as the system clock (φ).
Rev. 5.00, 12/03page 772 of 1088
DIV = 0
Bus master is in high-speed
mode (Initial value)
Medium-speed clock is φ/2
Medium-speed clock is φ/4
Medium-speed clock is φ/8
Medium-speed clock is φ/16
Medium-speed clock is φ/32
—
according to table 18-2. An AT-cut parallel-resonance
d
C
L1
R C
d L2
2 4 8
6.8 k 500 200
Description
DIV = 1
Bus master is in high-speed
mode
Clock supplied to entire chip is φ/2
Clock supplied to entire chip is φ/4
Clock supplied to entire chip is φ/8
—
—
—
C = C = 10 to 22 pF
L1 L2
12 16 20
0 0 0
(Initial value)
25
0