109
Serial I/O2
M
i
t
s
u
M
S
b
i
s
3
M
h
0
I
C
i
m
2
R
i
1
O
c
r
8
C
o
c
o
G
M
m
p
r
P
u
t
u
T
e
r
p
R
s
o
U
S
I
N
G
L
E
-
C
H
I
P
1
6
-
B
I
T
C
M
O
O
E
Handshake Signal
There are five types of handshake signal : S
STB2
output,
S
BUSY2
input/
output
,
and S
RDY2
input/output.
(1) S
STB2
output signal
The S
STB2
output is a signal to inform an end of transmission/reception to the serial transfer destina-
tion. The S
STB2
output signal can be used only when the internal synchronous clock is selected. In the
initial status [ serial I/O initialization bit (bit 4 of address 0342
16
) = “0” ], the S
STB2
output goes to “L”
(bits 2, 3 of address 0342
16
=11), or the S
STB2
output goes to “H” (bits 2, 3 of address 0342
16
=10).
At the end of transmit/receive operation, after the all data of the serial I/O2 register (
address 0346
16
)
is
output from S
OUT2
,
S
STB2
output is “H” (or S
STB2
output is “L”)
in the period of 1 cycle of the transfer clock.
Furthermore, after 1 cycle, the serial transfer status flag (bit 5
of address 0344
16
) is reset to “0”.
In the automatic transfer serial I/O mode, whether the S
STB2
output is to be output at an end of each 1-byte
data or after completion of transfer of all data can be selected by the S
BUSY2
output S
STB2
output function
select bit (bit 4 of address 0344
16
).
Figure 91. S
STB2
Output Operation
"1"
"0"
S
STB2
(output)
"H"
"L"
D
0
Tc
D
1
D
2
D
3
D
4
D
5
D
6
D
7
"1"
"0"
"H"
"L"
D
0
Tc
D
1
D
2
D
3
D
4
D
5
D
6
D
7
D
0
D
1
D
2
D
3
D
4
D
5
D
6
D
7
Automatic
transfer interval
Serial operation used S
STB2
output
Operation mode
Transfer clock
S
STB2
output timing
: 8-bit serial I/O mode
: Internal synchronous clock
: Each 1-byte data
Internal clock
Serial transfer status flag
(bit 5 at address 0344
16
)
S
CLK2i
(i=1, 2)(output)
S
OUT2
Tc : Internal synchronous clock is selected by bits 5 to 7 of address 0348
16
Serial operation used S
STB2
output
Operation mode
Transfer clock
S
STB2
output timing
: Automatic transfer serial I/O mode
: Internal synchronous clock
: Each transfer of all data
Internal clock
Serial transfer status flag
(bit 5 at address 0344
16
)
S
CLK2i
(i=1, 2)(output)
S
STB2
(output)
S
OUT2
Tc : Internal synchronous clock is selected by bits 5 to 7 of address 0348
16