Datasheet

Section 15 Serial Communication Interface (SCI)
Rev. 3.00 Sep. 28, 2009 Page 432 of 910
REJ09B0350-0300
Yes
[1]
No
Initialization
Start reception
[2]
No
Yes
Read RDRF flag in SSR
[4]
[5]
[6]
Clear RE bit in SCR to 0
Read ORER, PER, and
FER flags in SSR
Error processing
(Continued on next page)
[3]
Read receive data in RDR, and
clear RDRF flag in SSR to 0
No
Yes
PER ∨ FER ∨ ORER = 1
RDRF = 1
All data received?
[1] SCI initialization:
The RxD pin is automatically
designated as the receive data input
pin.
[2] [3] Receive error processing and
break detection:
If a receive error occurs, read the
ORER, PER, and FER flags in SSR to
identify the error. After performing the
appropriate error processing, ensure
that the ORER, PER, and FER flags
are all cleared to 0. Reception cannot
be resumed if any of these flags are
set to 1. In the case of a framing error,
a break can be detected by reading
the value of the input port
corresponding to the RxD pin.
[4] SCI status check and receive data
read:
Read SSR and check that RDRF = 1,
then read the receive data in RDR and
clear the RDRF flag to 0. Transition of
the RDRF flag from 0 to 1 can also be
identified by an RXI interrupt.
[5] Serial reception continuation
procedure:
To continue serial reception, before
the stop bit for the current frame is
received, read the RDRF flag, read
RDR, and clear the RDRF flag to 0.
Note: Do not write to SMR, SCR, BRR,
and SDCR from the start to the
end of reception except the
process of [6].
[Legend]
∨: Logical add (OR)
End reception
Figure 15.9 Sample Serial Reception Flowchart (1)