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HD614P080S---------------------------------------------------------------
ON or recovering from stop mode, apply RESET input more
than tRC to obtain the necessary time for oscillator stabiliza·
tion. In other cases, the MeV reset requires at least two instruc·
tions cycle time of RESET input.
Table 19 shows initialized items by MeV reset and each
status after reset.
OSC
I
[>
Oscillator
OSC.
<l
• INTERNAL OSCILLATOR CIRCUIT
Fig. 15 gives internal oscillator circuit. The oscillator type
can be selected from the followings; crystal resonator, or ceramic
fIlter resonator as shown in Table 20. In any cases, external
clock operation -is available.
Divider
circuit
1/8
Timing
generator
circuit
System
clock
Fig. 15 Internal Oscillator Circuit
External clock
operation
Ceramic filter
resonator
Crystal
resonator
Table 20 Oscillator Circuit Example
Circuit configuration
Oscillator
OSCI
Open
OSC.
CI
ceramicfc::::::l
filter
C2
GND
OSCI
OSC2
GND
ATcut parallel resonance crystal
~~
OS~~
OSC2
Co
Remarks
Ceramic filter: CSA 4.00MG (Murata)
Rf:
lMn ±2%
Cl:
33pF ± 20%
C~:
33pF ± 20%
Ceramic filter: CSA 6.00MG (Murata)
Rf:
lMn ±2%
Cl:
30pF ± 20%
C2:
30pF
±
20%
• Wiring between these pins and elements should be
as
short
as possible, and never cross the other wirings. (Refer to Fig. 16)
Crystal: 4.194304 (MHz)
NC·18C (Nihon Denpa Kogyo)
Rf:
lMn ± 2%
Cl :
22pF ± 20%
Cz :
22pF ± 20%
Crystal: 6.0
(MHz)
NC·18C (Nihon Denpa Kogyo)
Rf:
lMn ± 2%
Cl :
20pF ±20%
C2 :
20pF ± 20%
Crystal: AT cut parallel resonance crystal
Co: 7pF max.
Rs: lOOn max.
f:
2.0 ...... 6.2MHz
• Wiring between these pins and elements should be
as
short as
possible, and never cross the other wirings. (Refer to Fig. 16)
• PI ... conlUlt with the engineers of crystal or ceramic filter resonator maker to determine the value of Rf, C
I
and C •.
280
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