3069RF-ZTAT Datasheet, PDF (527/1003 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER

(3)
Error handling
Overrun error handling
Clear ORER flag to 0 in SSR
<End>
Figure 13.18 Sample Flowchart for Serial Receiving (2)
In receiving, the SCI operates as follows:
• The SCI synchronizes with serial clock input or output and synchronizes 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 checks fails (receive error), the SCI operates as shown in table
13.11.
When a receive error has been identified in the error check, subsequent transmit and receive
operations are disabled.
• When the RDRF flag is set to 1, if the RIE bit is set to 1 in SCR, a receive-data-full interrupt
(RXI) is requested. If the ORER flag is set to 1 and the RIE bit in SCR is also set to 1, a
receive-error interrupt (ERI) is requested.
Rev. 5.0, 09/04, page 505 of 978