Filter
Top Products
Rev. 1.0, 07/01, page 214 of 372
Yes
No
Start reception
No
Yes
[4]
Clear RE bit in SCR3 to 0
Error processing
[5]
Yes
No
FER+OER = 1
RDRF = 1
All data received?
Read MPIE bit in SCR3 [1]
[2]
Read OER and FER flags in SSR
Read RDRF flag in SSR [3]
Read receive data in RDR
No
Yes
[A]
This station’s ID?
Read OER and FER flags in SSR
Yes
No
Read RDRF flag in SSR
No
Yes
FER+OER = 1
Read receive data in RDR
RDRF = 1
[1] Set the MPIE bit in SCR to 1.
[2] Read OER and FER in SSR to check for
errors. Receive error processing is performed
in cases where a receive error occurs.
[3] 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.
When data is read from RDR, the RDRF flag
is automatically cleared to 0.
[4] Read SSR and check that the RDRF flag is
set to 1, then read the data in RDR.
[5] If a receive error occurs, read the OER and
FER flags in SSR to identify the error. After
performing the appropriate error processing,
ensure that the OER 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.
End
(Continued on next page)
Figure 14-17 Sample Multiprocessor Serial Reception Flowchart (1)