Hitachi H8S/2378, H8S/2378R Series Hardware Manual page 726

Start of 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]
Overrun error handling
Clear ORER flag in SSR to 0
Rev. 1.0, 09/01, page 682 of 904
Initialization
ORER = 1?
No
Error processing
(Continued below)
RDRF = 1?
Yes
Yes
<End>
Error handling
<End>
Figure 15.19 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
handling, clear the ORER flag to
[3]
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.
Receive error handling: