HD6432621 Hitachi, HD6432621 Datasheet - Page 723

• Manufacturer Part Number: HD6432621
• Description: (HD64F262x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

Note: A system clock frequency multiplied by the multiplication factor (STC1 and STC0) should
20.3
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.
20.3.1
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 20-2 Damping Resistance Value
Frequency (MHz)
R
Crystal Resonator: Figure 20-3 shows the equivalent circuit of the crystal resonator. Use a
crystal resonator that has the characteristics shown in table 20-3. The crystal resonator frequency
should not exceed 20 MHz.
d
( )
not exceed the maximum operating frequency defined in sections 21A and 21B, Electrical
Characteristics.
Oscillator
Connecting a Crystal Resonator
Figure 20-2 Connection of Crystal Resonator (Example)
XTAL
EXTAL
XTAL
Figure 20-3 Crystal Resonator Equivalent Circuit
R
4
500
d
L
d
according to table 20-2. An AT-cut parallel-resonance
C
C
C
C
L
0
L1
L2
8
200
AT-cut parallel-resonance type
R
s
C
12
0
L1
= C
EXTAL
L2
= 10 to 22pF
16
0
20
0
679