Hitachi F-ZTAT H8/3039 Series Hardware Manual page 383

Transmitting Serial Data (Synchronous Mode): Figure 11-16 shows a sample flowchart for
transmitting serial data and indicates the procedure to follow.
Initialize
Start transmitting
Read TDRE flag in SSR
TDRE = 1?
Yes
Write transmit data in
TDR and clear TDRE flag
to 0 in SSR
All data
transmitted?
Yes
Read TEND flag in SSR
TEND = 1?
Yes
Clear TE bit to 0 in SCR
End
Figure 11-16 Sample Flowchart for Serial Transmitting
374
1. SCI initialization: the transmit data output function
1
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
2
written, write data in TDR, then clear the TDRE flag
to 0.
No
No
3
No