Renesas SH7781 User Manual

Page 1110

21. Serial Communication Interface with FIFO (SCIF)

Rev.1.00 Jan. 10, 2008 Page 1080 of 1658
REJ09B0261-0100

Figure 21.10 shows an example of the operation for transmission in asynchronous mode.

0/1

TDFE

TEND

Serial
data

Start
bit

Data

Parity
bit

Stop
bit

Start
bit

Idle state
(mark state)

SCIF_TXD

Data

Parity
bit

Stop
bit

TXI interrupt
request

Data written to SCFTDR
and TDFE read as 1 then
cleared to 0 by TXI
interrupt handler

TXI interrupt
request

One frame

Figure 21.10 Example of SCIF Transmission Operation

(Example with 8-Bit Data, Parity, One Stop Bit)

4. When modem control is enabled, transmission can be stopped and restarted in accordance with

the

SCIF_CTS input value. When SCIF_CTS is set to 1 during transmission, the SCIF goes to

the mark state after transmission of one frame. When

SCIF_CTS is set to 0, the next transmit

data is output starting from the start bit.

Figure 21.11 shows an example of the operation when modem control is used.

Serial data

SCIF_TXD

SCIF_CTS

D7 0/1

Drive high before stop bit

Start
bit

Parity
bit

Stop
bit

Start
bit

Figure 21.11 Example of Operation Using Modem Control (

SCIF_CTS)

(Only in Channel 0)