HD6417660 RENESAS [Renesas Technology Corp], HD6417660 Datasheet - Page 505

• Manufacturer Part Number: HD6417660
• Description: Renesas 32-Bit RISC Microcomputer
• Manufacturer: RENESAS [Renesas Technology Corp]

2. Serial Data Transmission
Figure 16.3 shows a sample flowchart for serial transmission.
Use the following procedure for serial data transmission after enabling the SCIF for
transmission.
TDFE bit in SCSSR, then clear to 0
data to SCFTDR, read 1 from
set number) bytes of transmit
Clear TE bit in SCSCR to 0
Write (64 – transmit trigger
Read TEND bit in SCSSR
Read TDFE bit in SCSSR
Set SCPDR and SCPCR
Start of transmission
All data transmitted?
End of transmission
Break output?
TEND = 1?
TDFE = 1?
Figure 16.3 Sample Serial Transmission Flowchart
Yes
Yes
Yes
Yes
No
No
No
No
1
2
3
1.
2.
3.
SCIF status check and transmit data write:
Read the serial status register (SCSSR) and
check that the TDFE flag is set to 1, then write
transmit data to SCFTDR, read 1 from the TDFE
flag, then clear the flag to 0.
The number of data bytes that can be written is
64 – (transmit trigger set number).
Serial transmission continuation procedure:
To continue serial transmission, read 1 from the
TDFE flag to confirm that writing is possible, then
write data to SCFTDR, and then clear the TDFE
bit to 0.
Break output at the end of serial transmission:
To output a break in serial transmission, set the
port SC data register (SCPDR) and port SC
control register (SCPCR), then clear the TE bit in
SCSCR to 0.
In steps 1 and 2, it is possible to ascertain the
number of data bytes that can be written from the
number of transmit data bytes in SCFTDR
indicated by the upper 8 bits of SCFDR.
Rev. 1.00, 02/04, page 467 of 804