Rev. 5.00, 09/03, page 541 of 760
• Serial data transmission
Figure 16. 6 shows a sample flo wchart fo r seri al tra nsmis si on.
Use the following procedure for serial data transmission after enabling the SCIF for transmission.
1. SCIF status check and transmit data write:
Read serial status register (SCSSR) and check that the TDFE flag is set to 1, then write
transmit data to the transmit FIFO data register (SCFTDR), 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 th e TDFE flag to confirm that writing is possible,
then write data to SCFTDR, and then clear the TDFE flag to 0.
3. 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 to 0 in the serial control register (SCSCR). For
information on SCPDR and SCPCR, see section 16.2.8, Bit Rate Register (SCBRR).
In steps 1 and 2, it is possible to ascertain the number of data bytes that can be writt en from the
number of transmit data bytes in SCFTDR indicated by the upper 8 bits of the FIFO data count
register (SCF DR).