111
Serial I/O2
M
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t
s
u
M
S
b
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s
3
M
h
0
I
C
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m
2
R
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1
O
c
r
8
C
o
c
o
G
M
m
p
r
P
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t
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T
e
r
p
R
s
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U
S
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6
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Figure 94. S
BUSY2
Output Operation (1)
Figure 95. S
BUSY2
Output Operation (2)
Internal clock
"1"
"0"
"H"
"L"
D
0
Tc
TC : Internal synchronous clock is selected by bits 5 to 7 of address 0348
16
D
1
D
2
D
3
D
4
D
5
D
6
D
7
Serial operation used S
BUSY2
output
Operation mode
Transfer clock
S
BUSY2
output timing
: 8-bit serial I/O mode
: Internal synchronous clock
: Each 1-byte data
Serial transfer status flag
(bit 5 at address 0344
16
)
S
OUT2
S
CLK2i
(i = 1, 2)(output)
S
BUSY2
(output
)
"1"
"0"
"H"
"L"
D
0
S
OUT2
D
1
D
2
D
3
D
4
D
5
D
6
D
7
Write to serial I/O register
(Address 0346
16
)
Serial operation used S
BUSY2
output
Operation mode
Transfer clock
S
BUSY2
output timing
: 8-bit serial I/O mode
: External synchronous clock
: Each 1-byte data
Serial transfer status flag
(bit 5 at address 0344
16
)
S
CLK2i
(i = 1, 2)(Input)
S
BUSY2
(output)
(3) S
BUSY2
output signal
The S
BUSY2
output is a signal which requests to stop of transmission/reception to the serial transfer
destination. In the automatic transfer serial I/O mode, regardless of the internal or external synchro-
nous clock, whether the S
BUSY2
output is to be output at transfer of each 1-byte data or during transfer
of all data can be selected by the S
BUSY2
output S
STB2
output function select bit (bit 4 of address
0344
16
). In the initial status[ serial I/O initialization bit (bit 4 of address 0342
16
) = “0” ], the status in
which the S
BUSY2
outputs “H” (or the S
BUSY2
outputs “L”).
When the internal synchronous clock is selected, in the 8-bit serial I/O mode and the automatic trans-
fer serial I/O mode (S
BUSY2
output function: each 1-byte signal is selected), the S
BUSY2
output goes to
“L” (or the S
BUSY2
output goes to “H”) before 0.5 cycle of the timing at which the transfer clock goes to
“L” . In the automatic transfer serial I/O mode (the S
BUSY2
output function: all transfer data is selected),
the S
BUSY2
output goes to “L” (or the S
BUSY2
output goes to “H”) when the first transmit data is written
into the serial I/O2 register (address 0346
16
).
____________
When the external synchronous clock is selected, the S
BUSY2
output goes to “L” (or the S
BUSY2
output
goes to “H”) when transmit data is written into the serial I/O2 register(address 0346
16
), regardless of
the serial I/O transfer mode.
At termination of transmit/receive operation, in the 8-bit serial I/O mode, the S
BUSY2
output goes to “H”
(or the S
BUSY2
output returns to “L”), when the serial transfer status flag is set to “0”, regardless of
whether the internal or external synchronous clock is selected. Furthermore, in the automatic transfer
serial I/O mode (S
BUSY2
output function: each 1-byte signal is selected), the S
BUSY2
output goes to “H”
(or the S
BUSY2
output goes to “L”) each time 1-byte of receive data is written into the automatic trans-
fer RAM.