Datasheet

Table Of Contents
Section 17 Serial Communications Interface 3 (SCI3, IrDA)
Rev. 2.00 Jul. 04, 2007 Page 399 of 692
REJ09B0309-0200
17.6.2 Multiprocessor Serial Data Reception
Figure 17.17 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 RXI3 interrupt request is
generated at this time. All other SCI3 operations are the same as in asynchronous mode. Figure
17.18 shows an example of SCI3 operation for multiprocessor format reception.
Start reception
Read OER and FER flags in SSR
Read RDRF flag in SSR
Read RDRF flag in SSR
Read OER and FER flags in SSR
OER + FER = 1?
RDRF = 1?
RDRF = 1?
Data reception
continued?
OER = 1?
FER = 1?
Receive error
processing
OER + FER = 1?
This station's ID?
Read receive data in RDR
Read receive data in RDR
Clear RE bit in SCR to 0
End
Start receive error processing
End
Clear OER and FER flags
in SSR to 0
Set MPIE bit in SCR to 1[1]
[2]
[3]
[4]
[5]
(A)
(A)
Overrun error
processing
Framing error
processing
Break?
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
Yes
No
No
No
[1] Set the MPIE bit in SCR to 1.
[2] Read OER and FER in SSR to check
for errors. Receive error processing is
performed in cases where a receive
error occurs.
[4] Read SSR and check that the RDRF
flag is set to 1, then read the data in
RDR.
[3] Read SSR and check that the RDRF
flag is set to 1, then read the receive
data in RDR and compare it with this
station's ID.
If the data is not this station's ID, set
the MPIE bit to 1 again.
When data is read from RDR, the
RDRF flag is automatically cleared to
0.
[5] If a receive error occurs, read the OER
and FER flags in SSR to identify the
error. After performing the appropriate
error processing, ensure that the OER
and FER flags are all cleared to 0.
Reception cannot be resumed if either of
these flags is set to 1.
In the case of a framing error, a break
can be detected by reading the RXD3
pin value.
Figure 17.17 Sample Multiprocessor Serial Reception Flowchart (1)