Renesas H8S/2633 Series Hardware Manual page 804

Start reception
Read ORER flag in SSR
Read RDRF flag in SSR
No
Read receive data in RDR, and
clear RDRF flag in SSR to 0
No
All data received?
Clear RE bit in SCR to 0
[3]
Error processing
Overrun error processing
Clear ORER flag in SSR to 0
750
Initialization
ORER= 1
No
Error processing
(Continued below)
RDRF= 1
Yes
Yes
<End>
<End>
Figure 16-18 Sample Serial Reception Flowchart
[1] SCI initialization:
[1]
The RxD pin is automatically
designated as the receive data
input pin.
[2] [3]
[2]
If a receive error occurs, read the
ORER flag in SSR , and after
performing the appropriate error
Yes
processing, clear the ORER flag
[3]
to 0. Transfer cannot be resumed
if the ORER flag is set to 1.
[4]
SCI status check and receive
data read:
Read SSR and check that the
[4]
RDRF flag is set to 1, then read
the receive data in RDR and
clear the RDRF flag to 0.
Transition of the RDRF flag from
0 to 1 can also be identified by
an RXI interrupt.
[5] Serial reception continuation
procedure:
To continue serial reception,
before the MSB (bit 7) of the
current frame is received, finish
reading the RDRF flag, reading
[5]
RDR, and clearing the RDRF flag
to 0. The RDRF flag is cleared
automatically when the DMAC *
or DTC * is activated by a receive
data full interrupt (RXI) request
and the RDR value is read.
Note: * DMAC and DTC functions
Receive error processing:
are not available in the
H8S/2695.