Renesas SH7709S Manual Do Utilizador

Rev. 5.00, 09/03, page 476 of 760

Initialization

Clear TE and RE bits in SCSCR to 0

(1)

Has a 1-bit

period elapsed?

Set TE and RE bits in SCSCR to 1

and set RIE, TIE, TEIE, and MPIE bits

Set transmit/receive format in SCSMR

Yes

No

Set value in SCBRR

Set RIE, TIE, TEIE, MPIE, CKE1,

and CKE0 bits in SCSCR

(TE and RE are 0)

End

Wait

(2)

(3)

(4)

Note:  Numbers in parentheses refer to steps in the preceding procedure description.

Transmitting Serial Data (Synchronous Mode): Figure 14.19 shows a sample flowchart for
transmitting serial data. The procedure for transmitting serial data is:

1. SCI status check and transmit data write: Read the serial status register (SCSSR), check that

the TDRE bit is 1, then write transmit data in the transmit data register (SCTDR) 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 SCTDR, then clear TDRE to 0.