HT48RA0-2/HT48CA0-2
V
D
D
W
e
a
k
P
u
l
l
-
u
p
D
a
t
a
b
u
s
D
C
Q
P
A
0
~
P
A
7
P
B
0
~
P
B
1
W
r
i
t
e
K
Q
S
C
h
i
p
R
e
s
e
t
R
e
a
d
D
a
t
a
p
S
y
s
t
e
m
W
a
k
e
-
u
C
o
d
e
O
p
t
i
o
n
P
B
0
~
P
B
1
o
n
l
y
PA, PB Input/Output Lines
V
D
D
P
u
l
l
-
u
p
R
e
a
d
D
a
t
a
D
a
t
a
b
u
s
P
B
2
~
P
B
5
S
y
s
t
e
m
W
a
k
e
-
u
p
C
o
d
e
O
p
t
i
o
n
PB Input Lines
·
Low Voltage Reset - LVR
The LVR uses the ²OR² function with the external
RES signal to perform chip reset.
The microcontroller provides low voltage reset circuit in
order to monitor the supply voltage of the device. If the
supply voltage of the device is within the range
0.9V~VLVR, such as changing a battery, the LVR will au-
tomatically reset the device internally.
The relationship between VDD and VLVR is shown below.
V
D
D
3
.
6
V
The LVR includes the following specifications:
·
The low voltage (0.9V~VLVR) has to remain in their
original state to exceed 1ms. If the low voltage state
does not exceed 1ms, the LVR will ignore it and do not
perform a reset function.
V
L
V
R
1
.
9
V
0
.
9
V
Rev. 1.50
10
July 23, 2004
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
