Datasheet

Section 15 Serial Communication Interface (SCI, IrDA)
Rev.7.00 Mar. 18, 2009 page 737 of 1136
REJ09B0109-0700
15.5.2 Multiprocessor Serial Data Reception
Figure 15.13 shows a sample flowchart for multiprocessor serial data reception. If the MPIE bit in
SCR is set to 1, data is skipped until data with a 1 multiprocessor bit is received. On receiving data
with a 1 multiprocessor bit, the receive data is transferred to RDR. An RXI interrupt request is
generated at this time. All other SCI operations are the same as in asynchronous mode. Figure
15.12 shows an example of SCI operation for multiprocessor format reception.
MPIE
RDR
value
0
D0 D1 D7 1 1 0 D0 D1 D7 0 1
1 1
Data (ID1)Start
bit MPB
Stop
bit
Start
bit
Data (Data1)
MPB
Stop
bit
RXI interrupt
request
(multiprocessor
interrupt)
generated
MPIE = 0
Idle state
(mark state)
RDRF
RDR data read
and RDRF flag
cleared to 0 in
RXI interrupt
handling routine
If not this station’s ID,
MPIE bit is set to 1
again
RXI interrupt request is
not generated, and RDR
retains its state
ID1
(a) Data does not match stati
on’s ID
MPIE
RDR
value
0
D0 D1 D7 1 1 0 D0 D1 D7 0 1
1 1
Data (ID2)Start
bit
MPB
Stop
bit
Start
bit
Data (Data2)
MPB
Stop
bit
RXI interrupt
request
(multiprocessor
interrupt)
generated
MPIE = 0
Idle state
(mark state)
RDRF
RDR data read and
RDRF flag cleared
to 0 in RXI interrupt
handling routine
Matches this station’s ID,
so reception continues, and
data is received in RXI
interrupt handling routine
MPIE bit set to 1
again
ID2
(b) Data matches
station’s ID
Data2ID1
Figure 15.12 Example of SCI Operation in Reception
(Example with 8-Bit Data, Multiprocessor Bit, One Stop Bit)