Section 16 Serial Communication Interface 3 (SCI3)
Reception cannot be resumed while a receive error flag is set to 1. Accordingly, clear the OER,
FER, PER, and RDRF bits to 0 before resuming reception. Figure 16.13 shows a sample flow
chart for serial data reception.
Start reception
[1] Read the OER flag in SSR to determine if
there is an error. If an overrun error has
[1]
occurred, execute overrun error processing.
[2] Read SSR and check that the RDRF flag is
set to 1, then read the receive data in RDR.
When data is read from RDR, the RDRF
flag is automatically cleared to 0.
Read OER flag in SSR
Yes
OER = 1
No
[4]
[3] To continue serial reception, before the
MSB (bit 7) of the current frame is received,
reading the RDRF flag and reading RDR
should be finished. When data is read from
RDR, the RDRF flag is automatically
cleared to 0.
Error processing
(Continued below)
Read RDRF flag in SSR
[2]
[4] If an overrun error occurs, read the OER
flag in SSR, and after performing the
appropriate error processing, clear the OER
flag to 0. Reception cannot be resumed if
the OER flag is set to 1.
No
RDRF = 1
Yes
Read receive data in RDR
Yes
All data received?
No
[3]
Clear RE bit in SCR3 to 0
<End>
[4]
Error processing
Overrun error processing
Clear OER flag in SSR to 0
<End>
Figure 16.13 Sample Serial Reception Flowchart (Clock Synchronous Mode)
Rev. 3.00 Sep. 10, 2007 Page 315 of 528
REJ09B0216-0300
RENESAS [ RENESAS TECHNOLOGY CORP ]
