SH7125_08 Datasheet, PDF (477/774 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH™ RISC engine Family

Section 12 Serial Communication Interface (SCI)
Transmitting Serial Data (Clock Synchronous Mode): Figure 12.10 shows a sample flowchart
for transmitting serial data.
Use the following procedure for serial data transmission after enabling the SCI for transmission.
Start of transmission
Read TDRE flag in SCSSR
No
TDRE = 1?
Yes
Write transmit data to SCTDR
and clear TDRE flag
in SCSSR to 0
No
All data transmitted?
Yes
Read TEND flag in SCSSR
No
TEND = 1?
Yes
Clear TE bit in SCSCR to 0
[1] SCI status check and transmit data
write:
Read SCSSR and check that the
TDRE flag is set to 1, then write
transmit data to SCTDR, and clear
the TDRE flag to 0.
[2] Serial transmission continuation
procedure:
To continue serial transmission, read
1 from the TDRE flag to confirm that
writing is possible, then write data to
SCTDR, and then clear the TDRE
flag to 0.
End of transmission
Figure 12.10 Sample Flowchart for Transmitting Serial Data
Rev. 4.00 Jul. 25, 2008 Page 457 of 750
REJ09B0243-0400