Control Register File Extensions
2-25
CPU Data Paths and Control
SPRU733
Table 2
−
14. Floating-Point Adder Configuration Register (FADCR)
Field Descriptions (Continued)
Bit
Description
Value
Field
20
INVAL
0
A signed NaN (SNaN) is not a source.
1
A signed NaN (SNaN) is a source. NaN is a source in a floating-point to integer
conversion or when infinity is subtracted from infinity.
19
DEN2
Denormalized number select for .L2
src2
.
0
src2
is not a denormalized number.
1
src2
is a denormalized number.
18
DEN1
Denormalized number select for .L2
src1
.
0
src1
is not a denormalized number.
1
src1
is a denormalized number.
17
NAN2
NaN select for .L2
src2
.
0
src2
is not NaN.
1
src2
is NaN.
16
NAN1
NaN select for .L2
src1
.
0
src1
is not NaN.
1
src1
is NaN.
15
−
11 Reserved
0
Reserved. The reserved bit location is always read as 0. A value written to this
field has no effect.
10
−
9
RMODE
0
−
3h
Rounding mode select for .L1.
0
Round toward nearest representable floating-point number
1h
Round toward 0 (truncate)
2h
Round toward infinity (round up)
3h
Round toward negative infinity (round down)
8
UNDER
Result underflow status for .L1.
0
Result does not underflow.
1
Result underflows.