1. ID reception cycle: Set the MPIE
bit in SCSCR1 to 1.
Start of reception
2. SCI status check, ID reception
and comparison: Read SCSSR1
and SCSCR1, and check that the
RDRF flag is set to 1 and MPIE
bit is set to 0, then read the
Set MPIE bit in SCSCR1 to 1
Read ORER and FER flags
in SCSSR1
receive data in SCRDR1 and
compare it with this station’s ID.
Yes
FER = 1 or ORER = 1?
No
If the data is not this station’s ID,
set the MPIE bit to 1 again, and
clear the RDRF flag to 0. If the
data is this station’s ID, clear the
RDRF flag to 0.
Read RDRF flag in SCSSR1
Read MPIE bit in SCSCR1
No
No
3. SCI status check and data
reception: Read SCSSR1 and
check that the RDRF flag is set to
1, then read the data in SCRDR1.
RDRF = 1 and MPIE = 0?
Yes
Read receive data in SCRDR1
4. Receive error handling and break
detection: If a receive error
occurs, read the ORER and FER
flags in SCSSR1 to identify the
error. After performing the
This station’s ID?
Yes
Read ORER and FER flags
in SCSSR1
appropriate error handling,
ensure that the ORER and FER
flags are all cleared to 0.
Reception cannot be resumed if
either of these flags is set to 1. In
the case of a framing error, a
break can be detected by reading
the RxD pin value.
Yes
FER = 1 or ORER = 1?
No
Read RDRF flag in SCSSR1
No
No
RDRF = 1?
Yes
Read receive data in SCRDR1
All data received?
Yes
Error handling
End of reception
Figure 15.15 Sample Multiprocessor Serial Reception Flowchart (1)
Rev. 6.0, 07/02, page 639 of 986
RENESAS [ RENESAS TECHNOLOGY CORP ]
