Renesas RX100 Series User Manual page 665

RX13T Group
Figure 23.30 shows a sample flowchart for serial data reception.
Start data reception
Read ORER flag in SSR
SSR.ORER = 1
No
Read receive data in RDR
No
All data received?
Set bits RIE and RE in SCR to 0
[ 3 ]
Error processing
Overrun error processing
Clear the SSR.ORER flag to 0
Read the SSR.ORER flag
Figure 23.30 Example Flowchart of Serial Reception in Clock Synchronous Mode
R01UH0822EJ0100 Rev.1.00
Jul 31, 2019
Initialization
No
Error processing
(Continued below)
RXI interrupt
Yes
Yes
End
End
23. Serial Communications Interface (SCIg, SCIh)
[ 1 ] SCI initialization:
[ 1 ]
Make input port-pin settings for pins to be used
as RXDn pins.
[ 2 ] [ 3 ] Receive error processing:
If a receive error occurs, read the ORER flag in
the SSR register, perform the relevant error
[ 2 ]
processing, and then set the ORER flag to 0.
Data reception cannot be resumed while the
ORER flag is 1.
Yes
[ 3 ]
[ 4 ] Read the receive data in the RDR register once
in the receive data full interrupt (RXI) request
handling routine.
[ 5 ] Serial reception continuation procedure:
To continue serial reception, before the MSB (bit
7) of the current frame is received, finish reading
the receive data in the RDR register. The RDR
data can also be read by activating the DTC by
an RXI interrupt request.
[ 4 ]
[ 5 ]
[ 6 ] Processing in response to an overrun error:
[ 6 ]
Read the RDR register. In combination with step
[ 7 ], this will make correct reception of the next
frame possible.
[ 7 ]
[ 7 ] Clearing the error flag:
Write 0 to the error flag.
[ 8 ]
[ 8 ] Confirming that the error flag is cleared:
Read the error flag to confirm that its value is 0.
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