HD6473032F Datasheet, PDF (366/572 Pages) Hitachi Semiconductor – Hitachi Microcomputer

Transmitting and Receiving Data
Transmitting Multiprocessor Serial Data: Figure 11-10 shows a sample flowchart for
transmitting multiprocessor serial data and indicates the procedure to follow.
Initialize
Start transmitting
Read TDRE flag in SSR
No
TDRE = 1?
Yes
Write transmit data in
TDR and set MPBT bit in SSR
Clear TDRE flag to 0
No
All data transmitted?
Yes
Read TEND flag in SSR
No
TEND = 1?
Yes
No
Output break signal?
Yes
Clear DR bit to 0, set DDR bit to 1
1 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
2
flag is 1, then write transmit
data in TDR. Also set the MPBT flag to
0 or 1 in SSR. Finally, 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.
4. To output a break signal at the end of
serial transmission: set the DDR bit to
1 and clear the DR bit to 0 (DDR and
DR are I/O port registers), then clear
the TE bit to 0 in SCR.
3
4
Clear TE bit to 0 in SCR
End
Figure 11-10 Sample Flowchart for Transmitting Multiprocessor Serial Data
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