D12320VF25V Datasheet, PDF (512/1146 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 12 Serial Communication Interface (SCI)
Initialization
[1]
Start of reception
Read MPIE bit in SCR
[2]
Read ORER and FER flags in SSR
Yes
FER ∨ ORER = 1?
No
Read RDRF flag in SSR
[3]
No
RDRF = 1?
Yes
Read receive data in RDR
No
This station's ID?
Yes
Read ORER and FER flags in SSR
Yes
FER ∨ ORER = 1?
No
Read RDRF flag in SSR
[4]
No
RDRF = 1?
Yes
Read receive data in RDR
[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 stationÕs
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 handling 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
handling, ensure that the ORER
and FER flags are both 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.
No
All data received?
Yes
Clear RE bit in SCR to 0
<End>
[5]
Error handling
(Continued on
next page)
Figure 12.12 Sample Multiprocessor Serial Reception Flowchart
Rev.7.00 Feb. 14, 2007 page 478 of 1108
REJ09B0089-0700