SH7708 Datasheet, PDF (405/633 Pages) Renesas Technology Corp – SuperH™ RISC engine

Transmitting Serial Data (Synchronous Mode): Figure 13.16 shows a sample flowchart for
transmitting serial data. The procedure for transmitting serial data is:
1. SCI status check and transmit data write: Read the serial status register (SCSSR), check that
the TDRE bit is 1, then write transmit data in the transmit data register (SCTDR) and clear
TDRE to 0.
2. To continue transmitting serial data: Read the TDRE bit to check whether it is safe to write (if
it reads 1); if so, write data in SCTDR, then clear TDRE to 0.
Start transmission
Read TDRE bit in SCSSR
(1)
No
TDRE = 1?
Yes
Write transmit data to SCTDR
and clear TDRE bit in SCSSR to 0
All data transmitted?
No ₍₂₎
Yes
Read TEND bit in SCSSR
TEND = 1?
No
Yes
Clear TE bit in SCSCR to 0
End transmission
Note: Numbers in parentheses refer to the preceding procedure.
Figure 13.16 Sample Flowchart for Serial Transmitting
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