Datasheet

Table Of Contents
Section 17 Serial Communications Interface 3 (SCI3, IrDA)
Rev. 2.00 Jul. 04, 2007 Page 393 of 692
REJ09B0309-0200
17.5.4 Serial Data Reception (Clock Synchronous Mode)
Figure 17.12 shows an example of SCI3 operation for reception in clock synchronous mode. In
serial reception, the SCI3 operates as described below.
1. The SCI3 performs internal initialization synchronous with a synchronous clock input or
output, starts receiving data.
2. The SCI3 stores the received data in RSR.
3. If an overrun error occurs (when reception of the next data is completed while the RDRF flag
in SSR is still set to 1), the OER bit in SSR is set to 1. If the RIE bit in SCR is set to 1 at this
time, an ERI3 interrupt request is generated, receive data is not transferred to RDR, and the
RDRF flag remains to be set to 1.
4. If reception is completed successfully, the RDRF bit in SSR is set to 1, and receive data is
transferred to RDR. If the RIE bit in SCR is set to 1 at this time, an RXI3 interrupt request is
generated.
Bit 7 Bit 0 Bit 7 Bit 0 Bit 1 Bit 6 Bit 7
Serial
data
RDRF
OER
LSI
operation
RXI3 interrupt
request generated
RXI3 interrupt
request
generated
ERI interrupt request
generated by
overrun error
Overrun error
processing
RDRF flag
cleared
to 0
RDR data read RDR data has
not been read
(RDRF = 1)
User
processing
Serial
clock
1 frame
1 frame
Figure 17.12 Example of SCI3 Reception Operation in Clock Synchronous Mode