Hitachi H8S/2646 Hardware Manual page 517

Initialization
Start reception
Read ORER flag in SSR
ORER= 1
Read RDRF flag in SSR
No
RDRF= 1
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
Figure 13-18 Sample Serial Reception Flowchart
Yes
No
Error processing
(Continued below)
Yes
Yes
<End>
<End>
[1]
SCI initialization:
[1]
The RxD pin is automatically
designated as the receive data
input pin.
[2] [3]
Receive error processing:
[2]
If a receive error occurs, read the
ORER flag in SSR , and after
performing the appropriate error
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 DTC is
activated by a receive data full
interrupt (RXI) request and the
RDR value is read.
485