SH7713 datasheet(616/904 Pages) RENESAS

616 / 904 page

Section 16 Serial Communication Interface with FIFO (SCIF)

Rev.1.50 Aug. 30, 2006 Page 576 of 860

REJ09B0288-0150

2. When data is transferred from SCFTDR to SCTSR and transmission is started, consecutive

transmit operations are performed until there is no transmit data left in SCFTDR. When the

number of transmit data bytes in SCFTDR falls to or below the transmit trigger number set in

SCFCR, the TDFE flag is set. If the TIE bit in SCSCR is set to 1 at this time, a transmit-FIFO-

data-empty interrupt (TXI) request is generated. If and external clock is specified, the SCIF

outputs data in synchronization with the input clock. Serial transmit data is output in order

from LSB to MSB from the TxD pin.

3. The SCIF checks the SCFTDR transmit data at the timing for sending the last bit. If data is

present, the data is transferred from SCFTDR to SCTSR, the stop bit is sent, and then serial

transmission of the next frame is started.

If there is no transmit data, the TEND flag in SCFSR is set to 1, the stop bit is sent, and then

the state of the TxD pin is held.

4. After serial transmission has completed, the SCIFnCK pin is fixed to high.

Figure 16.14 shows an example of the SCIF transmit operation.

Serial

clock

Serial

data

TDFE

LSB

Bit 0

Bit 1

Bit 7

Bit 0

Bit 1

Bit 6

Bit 7

MSB

TEND

TXI

request

1 frame

TXI

request

TXI handling routine writes

data in SCFTDR and clears

the TDFE flag to 0

Figure 16.14 Example of the SCIF Transmit Operation

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