Renesas SH7781 用户手册
21. Serial Communication Interface with FIFO (SCIF)
Rev.1.00 Jan. 10, 2008 Page 1064 of 1658
REJ09B0261-0100
REJ09B0261-0100
21.3.10
Transmit FIFO Data Count Register n (SCTFDR)
SCTFDR is a 16-bit register that indicates the number of transmit data bytes stored in SCFTDR.
SCTFDR can always be read from the CPU.
0
1
2
3
4
5
6
7
8
9
10
11
12
13
15
14
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
T0
T1
T2
T3
T4
T5
T6
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
BIt:
Initial value:
R/W:
Bit Bit
Name
Initial
Value R/W
Value R/W
Description
15 to 7
—
All 0
R
Reserved
These bits are always read as 0. The write value
should always be 0.
should always be 0.
6 to 0
T6 to T0
All 0
R
These bits show the number of untransmitted data
bytes in SCFTDR. A value of H'00 indicates that there
is no transmit data, and a value of H'40 indicates that
SCFTDR is full of the maximum number (64 bytes) of
transmit data.
bytes in SCFTDR. A value of H'00 indicates that there
is no transmit data, and a value of H'40 indicates that
SCFTDR is full of the maximum number (64 bytes) of
transmit data.