374
3
End
Error handling
Overrun error handling
Clear ORER flag to 0 in SSR
Figure 11-18 Sample Flowchart for Serial Receiving (2)
In receiving, the SCI operates as follows.
•
The SCI synchronizes with serial clock input or output and initializes internally.
•
Receive data is stored in RSR in order from LSB to MSB.
After receiving the data, the SCI checks that the RDRF flag is 0 so that receive data can be
transferred from RSR to RDR. If this check passes, the RDRF flag is set to 1 and the received
data is stored in RDR. If the check does not pass (receive error), the SCI operates as indicated
in table 11-11. If any receive error is detected, the subsequent data transmission/reception is
disabled.
•
After setting the RDRF flag to 1, if the RIE bit is set to 1 in SCR, the SCI requests a receive-
data-full interrupt (RXI). If the ORER flag is set to 1 and the RIE bit in SCR is also set to 1,
the SCI requests a receive-error interrupt (ERI).