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Section 15 Serial Communication Interface with FIFO
R01UH0134EJ0400 Rev. 4.00 Page 757 of 2108
Sep 24, 2014
SH7262 Group, SH7264 Group
Receiving Serial Data (Asynchronous Mode)
Figures 15.7 and 15.8 show sample flowcharts for serial reception.
Use the following procedure for serial data reception after enabling reception.
Start of reception
Read ER, DR, BRK flags in
SCFSR and ORER
flag in SCLSR
ER, DR, BRK or ORER = 1?
Read RDF flag in SCFSR
RDF = 1?
Read receive data in
SCFRDR, and clear RDF
flag in SCFSR to 0
All data received?
Clear RE bit in SCSCR to 0
End of reception
Yes
No
Yes
Yes
No
No
Error handling
[1] Receive error handling and
break detection:
Read the DR, ER, and BRK
flags in SCFSR, and the
ORER flag in SCLSR, to
identify any error, perform the
appropriate error handling,
then clear the DR, ER, BRK,
and ORER flags to 0. In the
case of a framing error, a
break can also be detected by
reading the value of the RxD
pin.
[2] Status check and receive data
read:
Read SCFSR and check that
RDF flag = 1, then read the
receive data in SCFRDR, read
1 from the RDF flag, and then
clear the RDF flag to 0. The
transition of the RDF flag from
0 to 1 can also be identified by
a receive FIFO data full
interrupt (RXI).
[3] Serial reception continuation
procedure:
To continue serial reception,
read at least the receive
trigger set number of receive
data bytes from SCFRDR,
read 1 from the RDF flag, then
clear the RDF flag to 0. The
number of receive data bytes
in SCFRDR can be
ascertained by reading from
SCRFDR.
[1]
[2]
[3]
Figure 15.7 Sample Flowchart for Receiving Serial Data