HD6473032F16 Datasheet, PDF (505/847 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series

Section 13 Serial Communication Interface
Transmitting and Receiving Data
• Transmitting Multiprocessor Serial Data
Figure 13.10 shows a sample flowchart for transmitting multiprocessor serial data and
indicates the procedure to follow.
Initialize
1
Start transmitting
Read TDRE flag in SSR
2
No
TDRE = 1?
Yes
Write transmit data in
TDR and set MPBT bit in SSR
Clear TDRE flag to 0
No
All data transmitted?
3
Yes
Read TEND flag in SSR
No
TEND = 1?
Yes
No
Output break signal?
4
Yes
Clear DR bit to 0, set DDR bit to 1
Clear TE bit to 0 in SCR
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. 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. When the DMAC is activated by a
transmit-data-empty interrupt request (TXI)
to write data in TDR, the TDRE flag is
checked and cleared automatically.
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.
End
Figure 13.10 Sample Flowchart for Transmitting Multiprocessor Serial Data
Rev. 3.00 Mar 21, 2006 page 475 of 814
REJ09B0302-0300