Technical information
53
3886 Group
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
MITSUBISHI MICROCOMPUTERS
D-A CONVERTER
The 3886 group has two internal D-A converters (DA1 and DA2)
with 8-bit resolution.
The D-A converter is performed by setting the value in each D-A
conversion register. The result of D-A conversion is output from
the DA1 or DA2 pin by setting the DA output enable bit to “1”.
When using the D-A converter, the corresponding port direction
register bit (P56/DA1/PWM01 or P57/DA2/PWM11) must be set to
“0” (input status).
The output analog voltage V is determined by the value n (decimal
notation) in the D-A conversion register as follows:
V = VREF ✕ n/256 (n = 0 to 255)
Where VREF is the reference voltage.
At reset, the D-A conversion registers are cleared to “0016”, the
DA output enable bits are cleared to “0”, and the P56/DA1/PWM01
and P57/DA2/PWM11 pins become high impedance.
The DA output does not have buffers. Accordingly, connect an ex-
ternal buffer when driving a low-impedance load.
Set VCC to 4.0 V or more when using the D-A converter.
Fig. 50 Block diagram of D-A converter
Fig. 51 Equivalent connection circuit of D-A converter (DA1)
P
5
6
/
D
A
1
/
P
W
M
0
1
D
-
A
1
c
o
n
v
e
r
s
i
o
n
r
e
g
i
s
t
e
r
(
8
)
R
-
2
R
r
e
s
i
s
t
o
r
l
a
d
d
e
r
D
A
1
o
u
t
p
u
t
e
n
a
b
l
e
b
i
t
P
5
7
/
D
A
2
/
P
W
M
1
1
D
-
A
2
c
o
n
v
e
r
s
i
o
n
r
e
g
i
s
t
e
r
(
8
)
R
-
2
R
r
e
s
i
s
t
o
r
l
a
d
d
e
r
D
A
2
o
u
t
p
u
t
e
n
a
b
l
e
b
i
t
D
a
t
a
b
u
s
A
V
S
S
V
R
E
F
“
0
”
“
1
”
M
S
B
“
0
”
“
1
”
R
2
R
R
2
R
R
2
R
R
2
R
R
2
R
R
2
R
R
2
R2
R
L
S
B
2
R
P
5
6
/
D
A
1
/
P
W
M
0
1
D
-
A
1
c
o
n
v
e
r
s
i
o
n
r
e
g
i
s
t
e
r
D
A
1
o
u
t
p
u
t
e
n
a
b
l
e
b
i
t