
241
μ
PD17704, 17705, 17707, 17708, 17709
16.2.11 Operation of serial interface 0
Tables 16-4 through 16-6 outlines the operations in each communication mode.
Table 16-4. Outline of Operation in I
2
C Bus Mode
Operation Mode
I
2
C Bus Mode
Slave operation (SIO0MS = 0)
Master operation (SIO0MS = 1)
Reception
Transmission
Reception
Transmission
Item
(SIO0TX = 0)
(SIO0TX = 1)
(SIO0TX = 0)
(SIO0TX = 1)
Status of
SDA/P0A3
When P0ABIO3 = 0
Outputs contents of
When P0ABIO3 = 0
Outputs contents of
each pin
Floating
SIO0SFR at falling of
Floating
SIO0SFR at falling of
Waits for input of
external clock
Waits for input of
internal clock
external data
regardless of
external data
regardless of P0ABIO3
When P0ABIO3 = 1
P0ABIO3
When P0ABIO3 = 1
General-purpose
General-purpose
output port
output port
Outputs content of
Outputs content of
output latch
output latch
SCL/P0A2
When P0ABIO2 = 0
Outputs internal clock regardless of P0ABIO2
Floating
Waits for input of external data
When P0ABIO2 = 1
General-purpose output port
Outputs content of output latch
Clock counter
Incremented at rising of SCL pin
Operation of
Output
Not output
Shifted from MSB
Not output
Shifted from MSB
presettable
each time SCL falls
each time SCL falls
shift register 0
Input
Shifted from LSB each time SCL rise and is input
Wait operation
In wait
SCL and SDA pins
SCL pin is floated
SCL pin outputs low
SCL pin outputs low
status
are floated
and SDA pin retains
level and SDA pin is
level and SDA pin
Wait
SCL pin is floated
SCL pin is floated
SCL pin outputs
SCL pin outputs
released
and waits for input of
and waits for input of
internal clock.
internal clock.
external clock.
external clock.
SDA pin is floated
SDA pin outputs data
SDA pin is floated and
SDA pin outputs data
and waits for external
each time SCL pin falls
waits for external data
each time SCL pin falls
data
Acknowledge
ACK output at falling
ACK input at rising
ACK output at falling
ACK input at rising
of 8th clock
of 9th clock
of 8th clock
of 9th clock
– – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – –
– – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – –