HD6417727BP160CV Datasheet, PDF (652/1098 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH™ RISC engine Family/ SH7700 Series

Section 19 Serial Communication Interface with FIFO (SCIF)
In serial transmission, the SCIF operates as described below.
1. When data is written into the transmit FIFO data register 2 (SCFTDR2), the SCIF transfers the
data from SCFTDR2 to the transmit shift register 2 (SCTSR2) and starts transmitting.
Confirm that the TDFE flag in the serial status register 2 (SCSSR2) is set to 1 before writing
transmit data to SCFTDR2. The number of data bytes that can be written is (16 – transmit
trigger setting).
2. When data is transferred from SCFTDR2 to SCTSR2 and transmission is started, consecutive
transmit operations are performed until there is no transmit data left in SCFTDR2. When the
number of transmit data bytes in SCFTDR2 falls below the transmit trigger number set in the
FIFO control register 2 (SCFCR2), the TDFE flag is set. If the TIE bit in the serial control
register (SCSR2) is set to 1 at this time, a transmit-FIFO-data-empty interrupt (TXI) request is
generated.
The serial transmit data is sent from the TxD2 pin in the following order.
a. Start bit: One-bit 0 is output.
b. Transmit data: 8-bit or 7-bit data is output in LSB-first order.
c. Parity bit: One parity bit (even or odd parity) is output. (A format in which a parity bit is
not output can also be selected.)
d. Stop bit(s): One- or two-bit 1s (stop bits) are output.
e. Mark state: 1 is output continuously until the start bit that starts the next transmission is
sent.
3. The SCIF checks the SCFTDR2 transmit data at the timing for sending the stop bit. If data is
present, the data is transferred from SCFTDR2 to SCTSR2, 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 SCSSR2 is set to 1, the stop bit is sent, and then
the line goes to the mark state in which 1 is output continuously.
Figure 19.6 shows an example of the operation for transmission.
Rev.6.00 Mar. 27, 2009 Page 594 of 1036
REJ09B0254-0600