Datasheet

Section 15 Serial Communication Interface (SCI)
Rev. 3.00 Sep. 28, 2009 Page 438 of 910
REJ09B0350-0300
Yes
[1]
No
Initialization
Start reception
No
Yes
[4]
Clear RE bit in SCR to 0
Error processing
(Continued on next page)
[5]
No
Yes
FER ∨ ORER = 1
RDRF = 1
All data received?
Set MPIE bit in SCR to 1
[2]
Read ORER and FER flags in SSR
Read RDRF flag in SSR [3]
[6]
Read receive data in RDR
No
Yes
This station’s ID?
Read ORER and FER flags in SSR
Yes
No
Read RDRF flag in SSR
No
Yes
FER ∨ ORER = 1
Read receive data in RDR
RDRF = 1
[1] SCI initialization:
The RxD pin is automatically
designated as the receive data input
pin.
[2] ID reception cycle:
Set the MPIE bit in SCR to 1.
[3] SCI status check, ID reception and
comparison:
Read SSR and check that the RDRF
flag is set to 1, then read the receive
data in RDR and compare it with this
station’s ID.
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.
[4] SCI status check and data reception:
Read SSR and check that the RDRF
flag is set to 1, then read the data in
RDR.
[5] Receive error processing and break
detection:
If a receive error occurs, read the
ORER and FER flags in SSR to identify
the error. After performing the
appropriate error processing, 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.
Note: Do not write to SMR, SCR, BRR,
and SDCR from the start to the
end of reception except the
process of [6].
[Legend]
∨: Logical add (OR)
End reception
Figure 15.13 Sample Multiprocessor Serial Reception Flowchart (1)