393
RDRF
MPIE
RDR
value
ID1
ID2
Data2
0
1
1
1
1
0
1
MPB
MPB
Serial
data
Start
bit
Data ID2
Stop
bit
Start
bit
Data 2
Stop
bit
Idle (mark)
state
D
0
D
1
D
7
D
0
D
1
D
7
0
RXI request,
(multiprocessor
interrupt)
MPIE = 0
RXI interrupt
handler reads data
in RDR and clears
RDRF to 0
Own ID, so receving
continues, with data
received at each RXI
MPIE
bit is again
set to 1
MPB
Figure 13.13 Example of SCI Receive Operation (Own ID Matches Data) (8-Bit Data with
Multiprocessor Bit and One Stop Bit) (cont)
13.3.4
Synchronous Operation
In synchronous mode, the SCI transmits and receives data in synchronization with clock pulses.
This mode is suitable for high-speed serial communication.
The SCI transmitter and receiver share the same clock but are otherwise independent, so full
duplex communication is possible. The transmitter and receiver are also double buffered, so
continuous transmitting or receiving is possible by reading or writing data while transmitting or
receiving is in progress.
Figure 13.14 shows the general format in synchronous serial communication.
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