Hitachi F-ZTAT H8/3039 Series Hardware Manual page 380

Figure 11-13 shows an example of SCI receive operation using a multiprocessor format.
Start
1
bit
MPIE
RDRF
RDR value
Start
1
bit
MPIE
RDRF
RDR value
Figure 11-13 Example of SCI Receive Operation (8-Bit Data with Multiprocessor Bit and
Data (ID1)
0 D0 D1 D7
RXI request
(multiprocessor
interrupt), MPIE = 0
a. Own ID does not match data
Data (ID2)
0 D0 D1 D7
ID1
RXI request
(multiprocessor
interrupt), MPIE = 0
b. Own ID matches data
Stop Start
MPB Data (data1)
bit bit
1 1 0 D0
RXI handler reads
RDR data and clears
RDRF flag to 0
Stop Start
MPB
bit bit
1 1 0 D0
RXI interrupt handler
reads RDR data and
clears RDRF flag to 0
One Stop Bit)
Stop
MPB
bit
D1 D7 0 1
ID1
Not own ID, so No RXI request,
MPIE bit is set RDR not updated
to 1 again
Stop
Data (data2) MPB
bit
D1 D7 0 1
ID2
Own ID, so receiving
continues, with data
received by RXI
interrupt handler
1
Idle (mark)
state
1
Idle (mark)
state
Data 2
MPIE bit is set
to 1 again
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