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Section 14 Serial Communication Interface (SCI)
No
Read receive data in RDR, and
clear RDRF flag in SSR to 0
No
Rev. 1.00 May 09, 2008 Page 392 of 954
REJ09B0462-0100
Initialization
Start reception
Read ORER, PER, and
FER flags in SSR
PER ∨ FER ∨ ORER = 1
No
Error processing
(Continued on next page)
Read RDRF flag in SSR
RDRF = 1
Yes
All data received
Yes
Clear RE bit in SCR to 0
End reception
Figure 14.9 Sample Serial Reception Flowchart (1)
[1] SCI initialization:
[1]
The RxD pin is automatically
designated as the receive data input
pin.
[2] [3] Receive error processing and
break detection:
[2]
If a receive error occurs, read the
ORER, PER, and FER flags in SSR to
identify the error. After performing the
Yes
appropriate error processing, ensure
that the ORER, PER, and FER flags
[3]
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
[4]
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
[5]
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
[6]
end of transmission except the
process of [6].
[Legend]
∨: Logical add (OR)
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