243
μ
PD17704, 17705, 17707, 17708, 17709
Table 16-6. Outline of Operation in 3-Wire Serial I/O Mode
Operation Mode
3-Wire Serial I/O Mode
Slave operation (SIO0MS = 0)
Master operation (SIO0MS = 1)
Reception
Transmission
Reception
Transmission
Item
(SIO0TX = 0)
(SIO0TX = 1)
(SIO0TX = 0)
(SIO0TX = 1)
Status of
SCK0/P0A1
When P0ABIO1 = 0
Outputs internal clock regardless of P0ABIO1
each pin
Floating
Waits for input of external data
When P0ABIO1 = 1
General-purpose output port
Outputs contents of output latch
SO0/P0A0
When P0ABIO0 = 0
Outputs contents of
When P0ABIO0 = 0
Outputs contents of
General-purpose
SIO0SFR at falling
General-purpose
SIO0SFR at falling
input port
edge of external clock
input port
edge of internal
Floating
regardless of
Floating
clock regardless of
When P0ABIO0 = 1
P0ABIO0
When P0ABIO0 = 1
P0ABIO0
General-purpose
General-purpose
output port
output port
Outputs contents
Outputs contents
of output latch
of output latch
SI0/P0B3
When P0BBIO3 = 0
Floating
Waits for input of external data
When P0BBIO3 = 1
General-purpose output port
Outputs contents of output latch
Clock counter
Incremented at rising of SCK0 pin
Operation of
Output
Not output
Shifted from MSB
Not output
Shifted from MSB
presettable
each time SCK0 falls
each time SCK0 falls
shift register 0
Input
Shifted from LSB each time SCK0 falls and is input
Wait operation
In wait
SCK0 pin is floated.
SCK0 pin is floated.
SCK0 pin outputs high
SCK0 pin outputs high
status
SO0 pin as general-
SC0 pin retains its
level
level.
purpose port.
status.
SO0 pin as general-
SO0 pin retains its
SI0 pin is floated
SI0 pin is floated
purpose port.
status.
SI0 pin is floated
SI0 pin is floated
Wait
SCK0 pin is floated
SCK0 pin is floated
SCK0 pin is floated
SCK0 pin is floated
released
and waits for input of
and waits for input of
and waits for input of
and waits for input of
external clock.
external clock.
external clock.
external clock.
SO0 pin as general-
SO0 pin outputs data.
SO0 pin as general-
SO0 pin outputs data.
purpose port.
SI0 pin is floated and
purpose port.
SI0 pin is floated and
SI0 pin is floated and
waits for input of
SI0 pin is floated and
waits for input of
waits for input of
external data
waits for input of
external data
external data
external data
– – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – –
– – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – –