
41
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
3822 Group
MITSUBISHI MICROCOMPUTERS
RESET CIRCUIT
To reset the microcomputer, RESET pin should be held at an “L”
level for 2 µs or more. Then the RESET pin is returned to an “H”
level (the power source voltage should be between VCC(min.) and
5.5 V, and the quartz-crystal oscillator should be stable), reset is
released. After the reset is completed, the program starts from the
address contained in address FFFD16 (high-order byte) and ad-
dress FFFC16 (low-order byte). Make sure that the reset input
voltage meets VIL spec. when a power source voltage passes
VCC(min.).
Fig. 39 Reset Circuit Example
Fig. 40 Reset Sequence
P
o
w
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r
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n
P
o
w
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r
s
o
u
r
c
e
v
o
l
t
a
g
e
Reset input
voltage
P
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V
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.
0
V
0
V
V
CC
R
E
S
E
T
V
CC
R
E
S
E
T
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T
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t
A
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S
Y
N
C
φ
X
IN
XI
N
:
a
b
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u
t
8
0
0
0
c
y
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R
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1
:
T
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(
XI
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a
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f
(φ)
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(
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=
8
•
f
(φ)
2
:
T
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.
FFFC FFFD
A
D
H
,
A
DL
ADL
ADH
????
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