Hitachi SH7095 Hardware User Manual page 358

Note: Circled numbers refer to the preceding procedure.
Transmitting Serial Data (asynchronous mode): Figure 13.5 shows a sample flowchart for
transmitting serial data. The procedure for transmitting serial data is as follows:
1. SCI status check and transmit data write. read the serial status register (SSR), check that the
TDRE bit is 1, then write transmit data in the transmit data register (TDR) and clear TDRE
to 0.
2. To continue transmitting serial data. read the TDRE bit to check whether it is safe to write (if
it reads 1); if so, write data in TDR, then clear TDRE to 0. When the DMAC is started by a
transmit-data-empty interrupt request (TXI) in order to write data in TDR, the TDRE bit is
checked and cleared automatically.
3. To output a break at the end of serial transmission, clear TE to 0 in SCR.
Figure 13.4 Sample Flowchart for SCI Initialization
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