SH7604 Datasheet, PDF (352/633 Pages) Hitachi Semiconductor – Hardware Manual

Bit: 7
6
5
4
3
2
1
0
Bit name:
Initial value: 0
0
0
0
0
0
0
0
R/W: R
R
R
R
R
R
R
R
13.2.3 Transmit Shift Register (TSR)
The transmit shift register (TSR) transmits serial data. The SCI loads transmit data from the
transmit data register (TDR) into TSR, then transmits the data serially from the TxD pin, LSB (bit
0) first. After transmitting one data byte, the SCI automatically loads the next transmit data from
TDR into TSR and starts transmitting again. If the TDRE bit in SSR is 1, however, the SCI does
not load the TDR contents into TSR. The CPU cannot read or write to TSR directly.
Bit: 7
6
5
4
3
2
1
0
Bit name:
R/W: —
—
—
—
—
—
—
—
13.2.4 Transmit Data Register (TDR)
The transmit data register (TDR) is an 8-bit register that stores data for serial transmission. When
the SCI detects that the transmit shift register (TSR) is empty, it moves transmit data written in
TDR into TSR and starts serial transmission. Continuous serial transmission is possible by writing
the next transmit data in TDR during serial transmission from TSR.
The CPU can always read and write to TDR. TDR is initialized to H'FF by a reset and in standby
and module standby mode.
Bit: 7
6
5
4
3
2
1
0
Bit name:
Initial value: 1
1
1
1
1
1
1
1
R/W: R/W R/W R/W R/W R/W R/W R/W R/W
13.2.5 Serial Mode Register (SMR)
The serial mode register (SMR) is an 8-bit register that specifies the SCI serial communication
format and selects the clock source for the baud rate generator.
The CPU can always read and write to SMR. SMR is initialized to H'00 by a reset and in standby
and module standby mode.
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