D12320VF25IV Datasheet, PDF (685/1304 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 14 Serial Communication Interface (SCI)
No
No
[3]
Initialization
Start of reception
[1]
[1] SCI initialization:
The RxD pin is automatically
designated as the receive data
input pin.
Read ORER flag in SSR
[2]
ORER = 1?
Yes
[3]
No
Error processing
(Continued below)
Read RDRF flag in SSR
[4]
RDRF = 1?
Yes
[2] [3] Receive error handling:
If a receive error occurs, read the
ORER flag in SSR, and after
performing the appropriate error
handling, clear the ORER flag 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
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.
Read receive data in RDR, and
clear RDRF flag in SSR to 0
All data received?
Yes
Clear RE bit in SCR to 0
<End>
[5] Serial reception continuation
procedure:
To continue serial reception,
before the MSB (bit 7) of the
current frame is received, finish
[5]
reading the RDRF flag, reading
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.
Error handling
Overrun error handling
Clear ORER flag in SSR to 0
<End>
Note: * The DMAC is not supported in the H8S/2321.
Figure 14.18 Sample Serial Reception Flowchart
Rev.6.00 Sep. 27, 2007 Page 653 of 1268
REJ09B0220-0600