Datasheet

Section 13 Serial Communication Interface (SCI)
Rev. 3.00 Sep. 28, 2009 Page 295 of 710
REJ09B0384-0300
Yes
<End>
[1]
No
Initialization
Start reception
[2]
No
Yes
Read RDRF flag in SSR [4]
[5]
Clear RE bit in SCR to 0
Error processing
(Continued below)
[3]
Read receive data in RDR and
clear RDRF flag in SSR to 0
No
Yes
ORER = 1
RDRF = 1
All data received?
Read ORER flag in SSR
<End>
Error processing
Overrun error processing
Clear ORER flag in SSR to 0
[3]
[1] SCI initialization:
The RxD pin is automatically
designated as the receive data input
pin.
[2] [3] 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.
[4] 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.
[5] Serial reception continuation
procedure:
To continue serial reception, before
the MSB (bit 7) of the current frame is
received, reading the RDRF flag,
reading RDR, and clearing the RDRF
flag to 0 should be finished.
However, the RDRF flag is cleared
automatically when the DTC is
initiated by a receive data full interrupt
(RXI) and reads data from RDR.
Figure 13.19 Sample Serial Reception Flowchart