Specifications
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
MITSUBISHI MICROCOMPUTERS
7560 Group
42
D-A Converter
The 7560 group has a D-A converter with 8-bit resolution and 2
channels (DA
1, DA2).
The D-A converter is started by setting the value in the D-A con-
version register. When the DA1 output enable bit or the DA2 output
enable bit is set to “1”, the result of D-A conversion is output from
the corresponding DA pin. When using the D-A converter, set the
P5
6/DA1 pin and the P57/DA2 pin to input mode (set “0” to bits 6,
7 of port P5 direction register) and the pull-up resistor should be in
the OFF state (set “0” to bit 3 of PULL register B) previously.
The output analog voltage V is determined by the value n (base
10) in the D-A conversion register as follows:
V=V
REF ✕ n/256 (n=0 to 255)
Where VREF is the reference voltage.
At reset, the D-A conversion registers are set to “0016”, the DA1
output enable bit and the DA2 output enable bit are set to “0”, and
the P56/DA1 pin and the P57/DA2 pin goes to high impedance
state. The DA converter is not buffered, so connect an external
buffer when driving a low-impedance load.
■ Note on applied voltage to VREF pin
When these pins are used as D-A conversion output pins, the Vcc
level is recommended for the applied voltage to VREF pin.
When the voltage below Vcc level is applied, the D-A conversion
accuracy may be worse.
Fig. 43 Structure of D-A control register
Fig. 44 Block diagram of D-A converter
D
A
1
o
u
t
p
u
t
e
n
a
b
l
e
b
i
t
0
:
D
i
s
a
b
l
e
d
1
:
E
n
a
b
l
e
d
D
A
2
o
u
t
p
u
t
e
n
a
b
l
e
b
i
t
0
:
D
i
s
a
b
l
e
d
1
:
E
n
a
b
l
e
d
N
o
t
u
s
e
d
(
“
0
”
a
t
r
e
a
d
i
n
g
)
(
W
r
i
t
e
“
0
”
t
o
t
h
e
s
e
b
i
t
s
a
t
w
r
i
t
i
n
g
.
)
b
7
b
0
D
-
A
c
o
n
t
r
o
l
r
e
g
i
s
t
e
r
(
D
A
C
O
N
:
a
d
d
r
e
s
s
0
0
3
6
1
6
)
000000
D
a
t
a
b
u
s
P5
6
/DA
1
D-A1 conversion register (8)
R
-
2
R
r
e
s
i
s
t
o
r
l
a
d
d
e
r
DA
1
output enable bit
(DA1: address 0032
16
)
P5
7
/DA
2
D-A2 conversion register (8)
R
-
2
R
r
e
s
i
s
t
o
r
l
a
d
d
e
r
DA
2
output enable bit
(DA2: address 0033
16
)