Figure 12.11 shows an example of an SCI receive operation using a multiprocessor format (8-bit
data with multiprocessor bit and one stop bit).
Start
bit
Stop Start
MPB bit bit
Stop
MPB bit
Data (ID1)
D0 D1
Data (Data1)
D0 D1 D7
1
1
0
D7
1
1
0
0
1
Idle state
(mark)
MPIE
RDRF
RDR value
ID1
MPB detection RXI request
MPIE = 0
RXI handler reads
RDR data and clears MPIE is set to
RDRF to 0 1 again
Not own ID, so No RXI request,
RDR not updated
(Multiprocessor interrupt)
(a) Own ID does not match data
Start
bit
Stop Start
MPB bit bit
Stop
MPB bit
Data (ID2)
D0 D1
Data (Data2)
D0 D1 D7
1
1
0
D7
1
1
0
0
1
Idle state
(mark)
MPIE
RDRF
RDR value
ID2
Data 2
RXI handler reads
RDR data and clears continues, with data
RDRF to 0 received at each RXI
Own ID, so receiving MPIE set to
MPB detection RXI request
MPIE = 0
1 again
(Multiprocessor interrupt)
(b) Own ID matches data
Figure 12.11 Example of SCI Receive Operation
(8-Bit Data with Multiprocessor Bit and One Stop Bit)
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RENESAS [ RENESAS TECHNOLOGY CORP ]
