HD6413008VF25 Datasheet, PDF (414/688 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

12. Serial Communication Interface
Figure 12.13 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 ^{RXI interrupt request}
MPIE = 0
(multiprocessor interrupt)
RXI interrupt handler reads Not own ID, so MPIE
RDR data and clears
bit is set to 1 again
RDRF flag to 0
No RXI interrupt
request, RDR not
updated
1
MPIE
RDRF
a. Own ID does not match data
Start
bit
Data (ID2)
0 D0 D1
Stop Start
MPB bit bit Data (data2)
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
RXI interrupt handler
(multiprocessor interrupt) 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 12.13 Example of SCI Receive Operation
(8-Bit Data with Multiprocessor Bit and One Stop Bit)
Rev.4.00 Aug. 20, 2007 Page 368 of 638
REJ09B0395-0400