HD64F2168 Datasheet, PDF (444/874 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer

Initialization
Start reception
[1] SCI initialization:
[1]
The RxD pin is automatically
designated as the receive data input
pin.
[2] [3] Receive error processing:
Read ORER flag in SSR
[2]
If a receive error occurs, read the
ORER flag in SSR, and after
performing the appropriate error
ORER = 1
Yes
[3]
processing, clear the ORER flag to 0.
Transfer cannot be resumed if the
ORER flag is set to 1.
No
Error processing
[4] SCI status check and receive data
(Continued below)
read:
Read SSR and check that the RDRF
Read RDRF flag in SSR
[4]
flag is set to 1, then read the receive
data in RDR and clear the RDRF flag
No
RDRF = 1
to 0.
Transition of the RDRF flag from 0 to 1
can also be identified by an RXI
Yes
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
[5] Serial reception continuation
procedure:
To continue serial reception, before
the MSB (bit 7) of the current frame is
received, reading the RDRF flag,
reading RDR, and clearing the RDRF
[5]
flag to 0 should be finished.
However, the RDRF flag is cleared
automatically when the DTC is
initiated by a receive data full interrupt
(RXI) and reads data from RDR.
<End>
[3]
Error processing
Overrun error processing
Clear ORER flag in SSR to 0
<End>
Figure 14.22 Sample Serial Reception Flowchart
Rev. 3.00, 03/04, page 404 of 830