Hardware manual

Rev. 3.0, 09/98, page 217 of 361
Figure 10.11 shows an example of SCI receive operation using a multiprocessor format.
"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"
Mark (idle)
state
MPIE
RDRF
RDR value ID1
MPB detection,
MPIE = "0"
RXI request RXI handler reads
RDR data and clears
RDRF to "0"
Not own ID, so
MPIE is set to
"1" again
No RXI request,
RDR not updated
(Multiprocessor interrupt)
(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"
Mark (idle)
state
MPIE
RDRF
RDR value ID2
MPB detection,
MPIE = "0"
RXI request RXI handler reads
RDR data and clears
RDRF to "0"
Own ID, so receiving
continues, with data
received at each RXI
MPIE set to
"1" again
(Multiprocessor interrupt)
(a) Own ID does not match data
ID1 Data 2
Figure 10.11 Example of SCI Receive Operation
(eight-bit data with multiprocessor bit and one stop bit)