h8s-2138 Renesas Electronics Corporation., h8s-2138 Datasheet - Page 480

• Manufacturer Part Number: h8s-2138
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

Section 15 Serial Communication Interface (SCI, IrDA)
Serial Data Reception (Asynchronous Mode): Figure 15.7 shows a sample flowchart for serial
reception.
The following procedure should be used for serial data reception.
Rev. 4.00 Jun 06, 2006 page 426 of 1004
REJ09B0301-0400
No
No
Read receive data in RDR, and
clear RDRF flag in SSR to 0
PER
Clear RE bit in SCR to 0
Read RDRF flag in SSR
Read ORER, PER, and
Figure 15.7 Sample Serial Reception Data Flowchart
All data received?
FER flags in SSR
Start reception
Initialization
FER
RDRF = 1?
<End>
Yes
Yes
ORER = 1?
No
(Continued on next page)
Error handling
Yes
[1]
[2]
[4]
[5]
[3]
[1]
[2] [3]
[4]
[5]
SCI initialization:
The RxD pin is automatically
designated as the receive data
input pin.
break detection:
If a receive error occurs, read the
ORER, PER, and FER flags in
SSR to identify the error. After
performing the appropriate error
handling, ensure that the ORER,
PER, and FER flags are all
cleared to 0. Reception cannot
be resumed if any of these flags
are set to 1. In the case of a
framing error, a break can be
detected by reading the value of
the input port corresponding to
the RxD pin.
SCI status check and receive
data read :
Read SSR and check that RDRF
= 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.
Serial reception continuation
procedure:
To continue serial reception,
before the stop bit for the current
frame is received, read the
RDRF flag, read RDR, and clear
the RDRF flag to 0. The RDRF
flag is cleared automatically
when the DTC is activated by an
RXI interrupt and the RDR value
is read.
Receive error handling and