Table of Contents
Advertisement
Serial Data Transmission: Figure 16.8 shows a sample flowchart for serial transmission.
Use the following procedure for serial data transmission after enabling the SCIF for transmission.
Start of transmission
Read TDFE flag in SCFSR2
TDFE = 1?
Write transmit data (16 - transmit
trigger set number) to SCFTDR2,
read 1 from TDFE flag and TEND
flag in SCFSR2, then clear to 0
All data transmitted?
Read TEND flag in SCFSR2
TEND = 1?
Break output?
Clear SPB2DT to 0 and
set SPB2IO to 1
Clear TE bit in SCSCR2 to 0
End of transmission
No
Yes
No
Yes
No
Yes
No
Yes
Figure 16.8 Sample Serial Transmission Flowchart
1. SCIF status check and transmit data
write:
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.
The number of transmit data bytes
that can be written is 16 - (transmit
trigger set number).
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.
3. Break output at the end of serial
transmission:
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.
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.
Rev. 4.0, 04/00, page 599 of 850
Advertisement
Table of Contents
