RX610 Group
20. Serial Communications Interface (SCI)
R01UH0032EJ0120 Rev.1.20
Page 656 of 1006
Feb 20, 2013
20.4.4
Serial Data Reception (Clock Synchronous Mode)
Figure 20.17 shows an example of SCI operation for serial reception in clock synchronous mode.
In serial data reception, the SCI operates as described below.
1. The SCI performs internal initialization and starts receiving data in synchronization with a synchronization clock
input or output, and stores the receive data in RSR.
If an overrun error occurs, the ORER bit in SSR is set to 1. If the RIE bit in SCR is set to 1 at this time, an ERI
interrupt request is generated. Receive data is not transferred to RDR.
2. When reception finishes successfully, receive data is transferred to RDR. If the RIE bit in SCR is set to 1 at this
time, an RXI interrupt request is generated. Continuous reception is enabled by reading the receive data transferred
to RDR in this RXI interrupt processing routine before reception of the next receive data is completed.
1 frame
RXI interrupt signal
SSR.ORER flag
Serial data
Reception clock
Bit 7
Bit 0
Bit 7
Bit 0
Bit 1
Bit 7
Bit 6
RDR data read in RXI
interrupt processing
routine
RXI interrupt request
generated
RXI interrupt request
generated
ERI interrupt request
generated by overrun error
Note:
*
For the corresponding interrupt vector number, see section 10, Interrupt Control Unit (ICU).
Figure 20.17 Example of Operation for Serial Reception in Clock Synchronous Mode
Data transfer cannot be resumed while a receive error flag is set to 1. Accordingly, clear the ORER, FER, and PER bits in
SSR to 0 before resuming reception. Moreover, be sure to read the RDR during overrun error processing.
Figure 20.18 shows a sample flowchart for serial data reception.
Summary of Contents for RX600 Series
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