HD6433045 HITACHI [Hitachi Semiconductor], HD6433045 Datasheet - Page 643

• Manufacturer Part Number: HD6433045
• Description: Hitachi Single-Chip Microcomputer
• Manufacturer: HITACHI [Hitachi Semiconductor]

19.2 Oscillator Circuit
Clock pulses can be supplied by connecting a crystal resonator, or by input of an external clock
signal.
19.2.1 Connecting a Crystal Resonator
Circuit Configuration: A crystal resonator can be connected as in the example in figure 19-2.
The damping resistance Rd should be selected according to table 19-1. An AT-cut parallel-
resonance crystal should be used.
Table 19-1 Damping Resistance Value
Damping Resistance
Value
Rd
(Ω)
Note: A crystal resonator between 2 MHz and 18 MHz (between 2 MHz and 16 MHz for the flash
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.
For products
listed below *
HD64F3048
memory version) can be used. If the chip is to be operated at less than 2 MHz, the on-chip
frequency divider should be used. (A crystal resonator of less than 2 MHz cannot be used.)
* HD6473048, HD6433048, HD6433047, HD6433045, HD6433044
Figure 19-2 Connection of Crystal Resonator (Example)
EXTAL
XTAL
2
1 k
1 k
2 f ≤ 4
500
1 k
Rd
4 f ≤ 8
200
500
C
C
L1
L2
634
8 f ≤ 10
0
200
Frequency f (MHz)
C
L1
10 f ≤ 13 13 f ≤ 16 16 f ≤ 18
0
100
= C
L2
= 10 pF to 22 pF
0
0
0
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