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Read ORER flag in SSR
Read RDRF flag in SSR
No
Read receive data in RDR, and
clear RDRF flag in SSR to 0
No
All data received?
Clear RE bit in SCR to 0
[3]
Overrun error processing
Clear ORER flag in SSR to 0
642
Initialization
Start reception
ORER= 1
No
RDRF= 1
Yes
Yes
<End>
Error processing
<End>
Figure 16-18 Sample Serial Reception Flowchart
[1]
[1]
[2] [3]
[2]
Yes
[3]
Error processing
[4]
(Continued below)
[4]
[5]
[5]
SCI initialization:
The RxD pin is automatically
designated as the receive data
input pin.
Receive error processing:
If a receive error occurs, read the
ORER flag in SSR , and after
performing the appropriate error
processing, clear the ORER flag
to 0. Transfer cannot be resumed
if the ORER flag is set to 1.
SCI status check and receive
data read:
Read SSR and check that the
RDRF flag is set to 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.
Serial reception continuation
procedure:
To continue serial reception,
before the MSB (bit 7) of the
current frame is received, finish
reading the RDRF flag, reading
RDR, and clearing the RDRF flag
to 0. The RDRF flag is cleared
automatically when the DMAC or
DTC is activated by a receive
data full interrupt (RXI) request
and the RDR value is read.
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