Section 12 Serial Communication Interface (SCI)
Rev. 3.00 Sep. 27, 2007 Page 422 of 758
REJ09B0243-0300
12.3.7
Serial Status Register (SCSSR)
SCSSR is an 8-bit register that contains status flags to indicate the SCI operating state.
The CPU can always read and write to SCSSR, but cannot write 1 to status flags TDRE, RDRF,
ORER, PER, and FER. These flags can be cleared to 0 only after 1 is read from the flags. The
TEND flag is a read-only bit and cannot be modified.
Bit:
Initial value:
R/W:
7
6
5
4
3
2
1
0
1
0
0
0
0
1
0
0
R/(W)
*
R/(W)
*
R/(W)
*
R/(W)
*
R/(W)
*
R
R
R/W
TDRE
RDRF
ORER
FER
PER
TEND
MPB
MPBT
Note:
Writing 0 to this bit after reading it as 1 clears the flag and is the only allowed way.
*
Bit Bit
Name
Initial
value
R/W Description
7 TDRE
1 R/(W)
*
Transmit Data Register Empty
Indicates whether data has been transferred from the
transmit data register (SCTDR) to the transmit shift
register (SCTSR) and SCTDR has become ready to
be written with next serial transmit data.
0: Indicates that SCTDR holds valid transmit data
[Clearing condition]
•
When 0 is written to TDRE after reading TDRE = 1
1: Indicates that SCTDR does not hold valid transmit
data
[Setting conditions]
•
By a power-on reset or in standby mode
•
When the TE bit in SCSCR is 0
•
When data is transferred from SCTDR to SCTSR
and data can be written to SCTDR
Summary of Contents for SH7124 R5F7124
Page 2: ...Rev 3 00 Sep 27 2007 Page ii of xx ...
Page 8: ...Rev 3 00 Sep 27 2007 Page viii of xx ...
Page 36: ...Section 1 Overview Rev 3 00 Sep 27 2007 Page 16 of 758 REJ09B0243 0300 ...
Page 68: ...Section 2 CPU Rev 3 00 Sep 27 2007 Page 48 of 758 REJ09B0243 0300 ...
Page 108: ...Section 5 Exception Handling Rev 3 00 Sep 27 2007 Page 88 of 758 REJ09B0243 0300 ...
Page 166: ...Section 7 User Break Controller UBC Rev 3 00 Sep 27 2007 Page 146 of 758 REJ09B0243 0300 ...
Page 724: ...Section 20 List of Registers Rev 3 00 Sep 27 2007 Page 704 of 758 REJ09B0243 0300 ...
Page 772: ...Rev 3 00 Sep 27 2007 Page 752 of 758 REJ09B0243 0300 ...
Page 778: ...Rev 3 00 Sep 27 2007 Page 758 of 758 REJ09B0243 0300 ...
Page 781: ......