HD6473032F16 Datasheet, PDF (512/847 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series

Section 13 Serial Communication Interface
• Transmitting Serial Data (Synchronous Mode)
Figure 13.16 shows a sample flowchart for transmitting 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 clear TDRE flag
to 0 in SSR
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. 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.
All data
transmitted?
Yes
No
3
Read TEND flag in SSR
TEND = 1?
No
Yes
Clear TE bit to 0 in SCR
End
Figure 13.16 Sample Flowchart for Serial Transmitting
Rev. 3.00 Mar 21, 2006 page 482 of 814
REJ09B0302-0300