HD64F3028F25 Datasheet, PDF (529/925 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series

Figure 13.13 shows an example of SCI receive operation using a multiprocessor format.
1
MPIE
Start
bit
Data (ID1)
0 D0 D1
Stop
MPB _bit
D7 1 1
Start
bit ^{Data (data1)}
0 D0 D1
Stop
MPB _bit
1
D7 0 1 _{Idle (mark)}
state
RDRF
RDR value
ID1
MPB detection
MPIE = 0
RXI interrupt
request
(multiprocessor
interrupt)
RXI interrupt handler reads
RDR data and clears
RDRF flag to 0
Not own ID, so MPIE
bit is set to 1 again
No RXI interrupt
request, RDR not
updated
a. Own ID does not match data
1
MPIE
RDRF
Start
bit
Data (ID2)
0 D0 D1
Stop Start
MPB bit bit Data (data1)
D7 1 1 0 D0 D1
Stop
MPB _bit
1
D7 0 1
Idle (mark)
state
RDR value
ID1
ID2
Data2
MPB detection
MPIE = 0
RXI interrupt
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
Figure 13.13 Example of SCI Receive Operation
(8-Bit Data with Multiprocessor Bit and One Stop Bit)
Rev. 2.00, 09/03, page 497 of 890