D12320VF25V Datasheet, PDF (521/1146 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 12 Serial Communication Interface (SCI)
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] [3] Receive error handling:
[2]
If a receive error occurs, read the
ORER flag in SSR, and after
ORER = 1?
Yes
[3]
performing the appropriate error
handling, clear the ORER flag to
0. Transfer cannot be resumed if
No
Error processing
the ORER flag is set to 1.
(Continued below)
[4] SCI status check and receive
data read:
Read RDRF flag in SSR
[4]
Read SSR and check that the
RDRF flag is set to 1, then read
the receive data in RDR and
No
RDRF = 1?
clear the RDRF flag to 0.
Transition of the RDRF flag from
0 to 1 can also be identified by
Yes
an RXI interrupt.
Read receive data in RDR, and
clear RDRF flag in SSR to 0
No
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 DTC is
activated by a receive-data-full
interrupt (RXI) request and the
RDR value is read.
[3]
Error handling
Overrun error handling
Clear ORER flag in SSR to 0
<End>
Figure 12.18 Sample Serial Reception Flowchart
Rev.7.00 Feb. 14, 2007 page 487 of 1108
REJ09B0089-0700