Figure 13-13 shows an example of SCI receive operation using a multiprocessor format.
Figure 13-13 Example of SCI Receive Operation (8-Bit Data with Multiprocessor Bit and
One Stop Bit)
1
Start
bit
0
D0
D1
D7
1
Stop
bit
1
Data (ID1)
MPB
Start
bit
0
D0
D1
D7
0
Stop
bit
1
Data (data1)
MPB
1
Idle (mark)
state
MPIE
RDRF
RDR value
ID1
RXI request
(multiprocessor
interrupt)
MPB detection
MPIE= 0
MPB detection
MPIE= 0
RXI handler reads
RDR data and clears
RDRF flag to 0
Not own ID, so
MPIE bit is set
to 1 again
No RXI request,
RDR not updated
a. Own ID does not match data
1
Start
bit
0
D0
D1
D7
1
Stop
bit
1
Data (ID2)
MPB
Start
bit
0
D0
D1
D7
0
Stop
bit
1
Data (data2)
MPB
1
Idle (mark)
state
MPIE
RDRF
RDR value
ID2
RXI request
(multiprocessor
interrupt)
RXI interrupt handler
reads RDR data and
clears RDRF flag to 0
Own ID, so receiving
continues, with data
received by RXI
interrupt handler
MPIE bit is set
to 1 again
b. Own ID matches data
Data 2
481
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