Technical information

30
3886 Group
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
MITSUBISHI MICROCOMPUTERS
Serial I/O2
The serial I/O2 function can be used only for clock synchronous
serial I/O.
For clock synchronous serial I/O the transmitter and the receiver
must use the same clock. If the internal clock is used, transfer is
started by a write signal to the serial I/O2 register.
[Serial I/O2 Control Register (SIO2CON)]
001D
16
The serial I/O2 control register contains seven bits which control
various serial I/O functions.
Fig. 26 Structure of serial I/O2 control register
Fig. 27 Block diagram of serial I/O2 function
S
e
r
i
a
l
I
/
O
2
c
o
n
t
r
o
l
r
e
g
i
s
t
e
r
(
S
I
O
2
C
O
N
:
a
d
d
r
e
s
s
0
0
1
D
1
6)
b
7
I
n
t
e
r
n
a
l
s
y
n
c
h
r
o
n
o
u
s
c
l
o
c
k
s
e
l
e
c
t
i
o
n
b
i
t
s
0
0
0
:
f
(
XI
N)
/
8
(
f
(
XC
I
N)
/
8
i
n
l
o
w
-
s
p
e
e
d
m
o
d
e
)
0
0
1
:
f
(
X
I
N)
/
1
6
(
f
(
XC
I
N)
/
1
6
i
n
l
o
w
-
s
p
e
e
d
m
o
d
e
)
0
1
0
:
f
(
X
I
N)
/
3
2
(
f
(
XC
I
N)
/
3
2
i
n
l
o
w
-
s
p
e
e
d
m
o
d
e
)
0
1
1
:
f
(
X
I
N)
/
6
4
(
f
(
XC
I
N)
/
6
4
i
n
l
o
w
-
s
p
e
e
d
m
o
d
e
)
1
1
0
:
f
(
X
I
N)
/
1
2
8
(
f
(
XC
I
N)
/
1
2
8
i
n
l
o
w
-
s
p
e
e
d
m
o
d
e
)
1
1
1
:
f
(
X
I
N)
/
2
5
6
(
f
(
XC
I
N)
/
2
5
6
i
n
l
o
w
-
s
p
e
e
d
m
o
d
e
)
S
e
r
i
a
l
I
/
O
2
p
o
r
t
s
e
l
e
c
t
i
o
n
b
i
t
0
:
I
/
O
p
o
r
t
1
:
S
O
U
T
2,
SC
L
K
2
s
i
g
n
a
l
o
u
t
p
u
t
S
R
D
Y
2
o
u
t
p
u
t
e
n
a
b
l
e
b
i
t
0
:
I
/
O
p
o
r
t
1
:
S
R
D
Y
2
s
i
g
n
a
l
o
u
t
p
u
t
T
r
a
n
s
f
e
r
d
i
r
e
c
t
i
o
n
s
e
l
e
c
t
i
o
n
b
i
t
0
:
L
S
B
f
i
r
s
t
1
:
M
S
B
f
i
r
s
t
S
e
r
i
a
l
I
/
O
2
s
y
n
c
h
r
o
n
o
u
s
c
l
o
c
k
s
e
l
e
c
t
i
o
n
b
i
t
0
:
E
x
t
e
r
n
a
l
c
l
o
c
k
1
:
I
n
t
e
r
n
a
l
c
l
o
c
k
C
o
m
p
a
r
a
t
o
r
r
e
f
e
r
e
n
c
e
i
n
p
u
t
s
e
l
e
c
t
i
o
n
b
i
t
0
:
P
0
0/
P
3R
E
F
i
n
p
u
t
1
:
R
e
f
e
r
e
n
c
e
i
n
p
u
t
f
i
x
e
d
b
0
b
2
b
1
b
0
X
I
N
1
0
0
1
0
1
S
R
D
Y
2
S
C
L
K
2
0
1
1
/
8
1
/
1
6
1
/
3
2
1
/
6
4
1
/
1
2
8
1
/
2
5
6
X
C
I
N
1
0
0
0
0
1
D
a
t
a
b
u
s
S
e
r
i
a
l
I
/
O
2
i
n
t
e
r
r
u
p
t
r
e
q
u
e
s
t
S
e
r
i
a
l
I
/
O
2
p
o
r
t
s
e
l
e
c
t
i
o
n
b
i
t
S
e
r
i
a
l
I
/
O
c
o
u
n
t
e
r
2
(
3
)
S
e
r
i
a
l
I
/
O
2
r
e
g
i
s
t
e
r
(
8
)
S
y
n
c
h
r
o
n
i
z
a
t
i
o
n
c
i
r
c
u
i
t
S
e
r
i
a
l
I
/
O
2
p
o
r
t
s
e
l
e
c
t
i
o
n
b
i
t
S
e
r
i
a
l
I
/
O
2
s
y
n
c
h
r
o
n
o
u
s
c
l
o
c
k
s
e
l
e
c
t
i
o
n
b
i
t
S
R
D
Y
2
o
u
t
p
u
t
e
n
a
b
l
e
b
i
t
E
x
t
e
r
n
a
l
c
l
o
c
k
I
n
t
e
r
n
a
l
s
y
n
c
h
r
o
n
o
u
s
c
l
o
c
k
s
e
l
e
c
t
i
o
n
b
i
t
s
D
i
v
i
d
e
r
P
7
2
/
S
C
L
K
2
P
7
1
/
S
O
U
T
2
P
7
0
/
S
I
N
2
P
7
2
l
a
t
c
h
P
7
1
l
a
t
c
h
P
7
3
l
a
t
c
h
P
7
3
/
S
R
D
Y
2
/
I
N
T
2
1
M
a
i
n
c
l
o
c
k
d
i
v
i
d
e
r
a
t
i
o
s
e
l
e
c
t
i
o
n
b
i
t
s
(
N
o
t
e
)
N
o
t
e
:
T
h
e
s
e
b
i
t
s
s
e
l
e
c
t
a
n
y
o
f
t
h
e
h
i
g
h
-
s
p
e
e
d
m
o
d
e
,
t
h
e
m
i
d
d
l
e
-
s
p
e
e
d
m
o
d
e
,
a
n
d
t
h
e
l
o
w
-
s
p
e
e
d
m
o
d
e
.
T
h
e
s
e
a
r
e
a
s
s
i
g
n
e
d
t
o
b
i
t
s
7
a
n
d
6
o
f
t
h
e
C
P
U
m
o
d
e
r
e
g
i
s
t
e
r
(
a
d
d
r
e
s
s
0
0
3
B
1
6
)
.