Serial Data Transmission: Figure 16.7 shows a sample flowchart for serial transmission.
Use the following procedure for serial data transmission after enabling the SCIF for transmission.
1. SCIF status check and transmit data
write:
Start of transmission
Read SCFSR2 and check that the
TDFE flag is set to 1, then write
transmit data to SCFTDR2, read 1
from the TDFE and TEND flags, then
clear these flags to 0.
Read TDFE flag in SCFSR2
No
TDFE = 1?
Yes
The number of transmit data bytes
that can be written is 16 - (transmit
trigger set number).
Write transmit data (16 - transmit
trigger set number) to SCFTDR2,
read 1 from TDFE flag and TEND
flag in SCFSR2, then clear to 0
2. Serial transmission continuation
procedure:
To continue serial transmission, read
1 from the TDFE flag to confirm that
writing is possible, then write data to
SCFTDR2, and then clear the TDFE
flag to 0.
No
All data transmitted?
Yes
3. Break output at the end of serial
transmission:
Read TEND flag in SCFSR2
To output a break in serial
transmission, clear the SPB2DT bit to
0 and set the SPB2IO bit to 1 in
SCSPTR2, then clear the TE bit in
SCSCR2 to 0.
No
No
TEND = 1?
Yes
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 SCFTDR2
indicated by the upper 8 bits of
SCFDR2.
Break output?
Yes
Clear SPB2DT to 0 and
set SPB2IO to 1
Clear TE bit in SCSCR2 to 0
End of transmission
Figure 16.7 Sample Serial Transmission Flowchart
Rev. 6.0, 07/02, page 690 of 986
RENESAS [ RENESAS TECHNOLOGY CORP ]
