Hitachi H8/329 Series Hardware Manual page 257

Figure 13-2. Connection of Crystal Oscillator (Example)
Crystal Oscillator: Figure 15-3 shows an equivalent circuit of the external crystal. The
external crystal should have the characteristics listed in table 13-1.
Table 13-1. External Crystal Parameters
Frequency (MHz)
Rs max (Ω)
C (pF)
0
XTAL
Figure 13-3. Equivalent Circuit of External Crystal
Note on Board Design: When an external crystal is connected, other signal lines should be
kept away from the crystal circuit to prevent induction from interfering with correct oscillation.
See figure 13-4. The crystal and its load capacitors should be placed as close as possible to the
XTAL and EXTAL pins.
EXTAL
XTAL
2 4 8
500 120 60
7 pF max
C
L
L
C
L1
C
L2
C = C = 10 to 22pF
L1 L2
12 16 20
40 30 20
R
S
C
0
AT-cut parallel resonating crystal
248
EXTAL