Datasheet

Section 13 Serial Communication Interface (SCI)
Rev. 3.00 Sep. 28, 2009 Page 287 of 710
REJ09B0384-0300
Yes
<End>
[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]
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.
[Legend]
∨ : Logical add (OR)
Figure 13.13 Sample Multiprocessor Serial Reception Flowchart (1)