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