HD643303x Hitachi, HD643303x Datasheet - Page 373

• Manufacturer Part Number: HD643303x
• Description: Hitachi Microcomputer
• Manufacturer: Hitachi

Transmitting Serial Data (Synchronous Mode): Figure 11-16 shows a sample flowchart for
transmitting serial data and indicates the procedure to follow.
TDR and clear TDRE flag
Read TDRE flag in SSR
Read TEND flag in SSR
Clear TE bit to 0 in SCR
Write transmit data in
Start transmitting
transmitted?
to 0 in SSR
TDRE = 1?
TEND = 1?
Initialize
All data
End
Yes
Yes
Yes
Figure 11-16 Sample Flowchart for Serial Transmitting
No
No
No
1
2
3
1.
2.
3.
358
SCI initialization: the transmit data output function
of the TxD pin is selected automatically.
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.
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.