Datasheet

Section 10 Serial Communication Interface
Rev. 6.00 Aug 04, 2006 page 338 of 680
REJ09B0145-0600
Bit 1: Tail mark transmission flag (MTRF)
When MRKON = 1, bit 1 indicates that a tail mark is being transmitted. MTRF is a read-only bit,
and cannot be modified.
Bit 1
MTRF Description
0 Idle state, or 8-bit/16-bit data transfer in progress (initial value)
1 Tail mark transmission in progress
Bit 0: Start flag (STF)
The STF bit controls the start of transfer operations. SCI1 transfer operation is started when this
bit is set to 1.
STF remains set to 1 during transfer and while SCI1 is waiting for a start bit, and is cleared to 0
when transfer ends.
Bit 0
STF Description
0 Read Transfer operation stopped (initial value)
Write Invalid
1 Read Transfer operation in progress
Write Starts transfer operation
3. Serial Data Register U (SDRU)
Bit
Initial value
Read/Write
7
SDRU7
Undefined
R/W
6
SDRU6
Undefined
R/W
5
SDRU5
Undefined
R/W
4
SDRU4
Undefined
R/W
3
SDRU3
Undefined
R/W
0
SDRU0
Undefined
R/W
2
SDRU2
Undefined
R/W
1
SDRU1
Undefined
R/W
SDRU is an 8-bit read/write register used as the data register for the upper 8 bits in 16-bit transfer
(while SDRL is used for the lower 8 bits).
The data written into SDRU is output to SDRL in LSB-first order. In the replacement process, data
is input LSB-first from the SI
1
pin, and the data is shifted in the MSB → LSB direction.