HD6413008VF25 Datasheet, PDF (417/688 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

12. Serial Communication Interface
• Transmitting Serial Data (Synchronous Mode): Figure 12.16 shows a sample flowchart for
transmitting serial data and indicates the procedure to follow.
Initialize
(1)
Start transmitting
Read TDRE flag in SSR
(2)
TDRE = 1
No
Yes
Write transmit data in TDR
and clear TDRE flag to 0 in SSR
(1) SCI initialization: the transmit data
output function of the TxD pin is
selected automatically.
(2) SCI status check and transmit data
write: read SSR, check that the TDRE
flag is 1, then write transmit data in
TDR and clear the TDRE flag to 0.
(3) To continue transmitting serial data:
after checking that the TDRE flag is 1,
indicating that data can be written,
write data in TDR, then clear the TDRE
flag to 0.
All data transmitted?
Yes
No
(3)
Read TEND flag in SSR
No
TEND = 1
Yes
Clear TE bit to 0 in SCR
<End>
Figure 12.16 Sample Flowchart for Serial Transmitting
Rev.4.00 Aug. 20, 2007 Page 371 of 638
REJ09B0395-0400