SH7211 Datasheet, PDF (695/1228 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperHTM RISC engine Family

Section 15 Serial Communication Interface with FIFO (SCIF)
15.3.3 Transmit Shift Register (SCTSR)
SCTSR transmits serial data. The SCIF loads transmit data from the transmit FIFO data register
(SCFTDR) into SCTSR, then transmits the data serially from the TXD pin, LSB (bit 0) first. After
transmitting one data byte, the SCIF automatically loads the next transmit data from SCFTDR into
SCTSR and starts transmitting again.
The CPU cannot read or write to SCTSR directly.
Bit: 7
6
5
4
3
2
1
0
Initial value: -
-
-
-
-
-
-
-
R/W: -
-
-
-
-
-
-
-
15.3.4 Transmit FIFO Data Register (SCFTDR)
SCFTDR is a 16-byte FIFO register that stores data for serial transmission. When the SCIF detects
that the transmit shift register (SCTSR) is empty, it moves transmit data written in the SCFTDR
into SCTSR and starts serial transmission. Continuous serial transmission is performed until there
is no transmit data left in SCFTDR. The CPU can write to SCFTDR at all times.
When SCFTDR is full of transmit data (16 bytes), no more data can be written. If writing of new
data is attempted, the data is ignored.
SCFTDR is initialized to an undefined value by a power-on reset.
Bit: 7
6
5
4
3
2
1
0
Initial value: -
-
-
-
-
-
-
-
R/W: W W W W W W W W
Rev. 2.00 May. 08, 2008 Page 671 of 1200
REJ09B0344-0200