Figure 15.10 Sample Serial Reception Flowchart (1) - Hitachi SH7751 Hardware Manual

Start of reception
Read ORER, PER, and FER flags
or ORER = 1?
Read RDRF flag in SCSSR1
No
Read receive data in SCRDR1,
and clear RDRF flag
in SCSSR1 to 0
No
All data received?
Clear RE bit in SCSCR1 to 0
End of reception
Rev. 3.0, 04/02, page 606 of 1064
in SCSSR1
PER or FER
No
RDRF = 1?
Yes
Yes

Figure 15.10 Sample Serial Reception Flowchart (1)

1. Receive error handling and
break detection: If a receive
error occurs, read the ORER,
PER, and FER flags in
SCSSR1 to identify the error.
After performing the
appropriate error handling,
ensure that the ORER, PER,
Yes
and FER flags are all cleared to
0. Reception cannot be
resumed if any of these flags
Error handling
are set to 1. In the case of a
framing error, a break can be
detected by reading the value
of the RxD pin.
2. SCI status check and receive
data read : Read SCSSR1 and
check that RDRF = 1, then read
the receive data in SCRDR1
and clear the RDRF flag to 0.
3. Serial reception continuation
procedure: To continue serial
reception, complete zero-
clearing of the RDRF flag
before the stop bit for the
current frame is received. (The
RDRF flag is cleared
automatically when the direct
memory access controller
(DMAC) is activated by an RXI
interrupt and the SCRDR1
value is read.)