HD6417706 RENESAS [Renesas Technology Corp], HD6417706 Datasheet - Page 423

• Manufacturer Part Number: HD6417706
• Description: Renesas 32-Bit RISC Microcomputer Super RISC engine Family/SH7700 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

Transmitting Serial Data (Asynchronous Mode): Figure 14.8 shows a sample flowchart for
transmitting serial data. Serial data transmission should be carried out in the following procedure
after setting the SCI in a transmission-enabled state.
SCTDR and clear TDRE bit in
Read TDRE bit in SCSSR
Write transmission data to
Read TEND bit in SCSSR
Set SCPDR and SCPCR
Clear TE bit SCSCR to 0
Figure 14.8 Sample Flowchart for Transmitting Serial Data
All data transmitted?
Start transmission
End transmission
Break output?
SCSSR to 0
TEND = 1?
TDRE = 1?
Yes
Yes
Yes
Yes
No
No
No
No
1.
2.
3.
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 SCTDR and clear
TDRE to 0.
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.
To output a break at the end of serial
transmission: Set the SCPCR and
SCPDR, then clear the TE bit to 0 in SCSCR.
For SCPCR and SCPDR settings, see14.3.8,
SC Port Control Register (SCPCR),
and 14.3.9, SC Port Data Register (SCPDR).
Rev. 4.00, 03/04, page 377 of 660