HD6417034B RENESAS [Renesas Technology Corp], HD6417034B Datasheet - Page 408

• Manufacturer Part Number: HD6417034B
• Description: 32-Bit RISC Microcomputer
• Manufacturer: RENESAS [Renesas Technology Corp]

Section 13 Serial Communication Interface (SCI)
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 initialization: select the TxD pin function with the PFC.
2. SCI status check and transmit data write: read the serial status register (SSR), check that the
3. To continue transmitting serial data: read the TDRE bit to check whether it is safe to write (1);
4.
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TDRE bit is 1, then write transmit data in the transmit data register (TDR) and clear TDRE to
0.
if so, write data in TDR, then clear TDRE to 0. When the DMAC is started by a transmit-data-
empty interrupt request (TXI) to write data in TDR, the TDRE bit is checked and cleared
automatically.
To output a break signal at the end of serial transmission: set the DR bit to 0, then clear TE to
0 in SCR and set the TxD pin function as output port with the PFC.
Figure 13.4 Sample Flowchart for SCI Initialization
Select communication format in SMR
Set TE or RE to 1 in SCR; Set RIE,
TIE, TEIE, and MPIE as necessary
Clear TE and RE bits to 0 in SCR
Set CKE1 and CKE0 bits in SCR
(leaving TE and RE cleared to 0)
1-bit interval elapsed?
Start of initialization
Set value in BRR
End
Yes
Wait
No
(1)
(2)
(3)
(4)