HD6417641 RENESAS [Renesas Technology Corp], HD6417641 Datasheet - Page 791

• Manufacturer Part Number: HD6417641
• Manufacturer: RENESAS [Renesas Technology Corp]

• Transmitting and Receiving Serial Data Simultaneously (Synchronous Mode)
Figure 19.18 shows a sample flowchart for transmitting and receiving serial data simultaneously.
Use the following procedure for the simultaneous transmission/reception of serial data, after
enabling the SCIF for transmission/reception.
Figure 19.18 Sample Flowchart for Transmitting/Receiving Serial Data
No
No
No
Start of transmission and reception
End of transmission and reception
Write transmit data to SCFTDR,
Read ORER flag in SCLSR
Read TDFE flag in SCFSR
Read RDF flag in SCFSR
SCFRDR, and clear RDF
Clear TE and RE bits
and clear TDFE flag
Read receive data in
flag in SCFSR to 0
All data received?
in SCSCR to 0
in SCFSR to 0
ORER = 1?
Initialization
TDFE = 1?
RDF = 1?
Yes
No
Yes
Yes
[1]
Error handling
[4]
[3]
Section 19 Serial Communication Interface with FIFO (SCIF)
Yes
[2]
Note:
[1] SCIF status check and transmit data
[2] Receive error handling:
[3] SCIF status check and receive data
[4] Serial transmission and reception
Read SCFSR and check that the
To continue serial transmission and
write:
TDFE flag is set to 1, then write
transmit data to SCFTDR, and clear
the TDFE flag to 0. The transition of
the TDFE flag from 0 to 1 can also be
identified by a TXI interrupt.
identify any error, perform the
appropriate error handling, then clear
the ORER flag to 0. Reception cannot
be resumed while the ORER flag is
set to 1.
read:
1, then read the receive data in
SCFRDR, and clear the RDF flag to
0. The transition of the RDF flag from
0 to 1 can also be identified by an RXI
interrupt.
continuation procedure:
reception, read 1 from the RDF flag
and the receive data in SCFRDR, and
clear the RDF flag to 0 before
receiving the MSB in the current
frame. Similarly, read 1 from the
TDFE flag to confirm that writing is
possible before transmitting the MSB
in the current frame. Then write data
to SCFTDR and clear the TDFE flag
to 0.
Read the ORER flag in SCLSR to
Read SCFSR and check that RDF =
When switching from a transmit operation
or receive operation to simultaneous
transmission and reception operations,
clear the TE and RE bits to 0, and then
set them simultaneously to 1.
Rev. 4.00 Sep. 14, 2005 Page 741 of 982
REJ09B0023-0400