Altera Floating-Point User Manual
Page 54
Parameter Name
Type
Required
Description
WIDTH_EXP
Integer
No
Specifies the precision of the exponent. The bias of
the exponent is always set to
2
(WIDTH_EXP-1) -
1
(that is,
127
for single-precision format and
1023
for
double-precision format). The
WIDTH_EXP
parameter
must be
8
for the single-precision mode and
11
for
the double-precision mode, or a minimum of
11
for
the single-extended precision mode. The
WIDTH_EXP
parameter must be less than the
WIDTH_MAN
parameter. The sum of
WIDTH_EXP
and the
WIDTH_
MAN
parameters must be less than
64
. If this
parameter is not specified, the default is
8
.
WIDTH_MAN
Integer
No
Specifies the precision of the mantissa. The
WIDTH_
MAN
parameter must be
23
(to comply with the IEEE-
754 standard for the single-precision mode) when
the
WIDTH_EXP
parameter is
8
. Otherwise, the
WIDTH_
MAN
parameter must have a value that is greater than
or equal to
31
. The
WIDTH_MAN
parameter must be
greater than the
WIDTH_EXP
parameter. The sum of
the
WIDTH_EXP
and
WIDTH_MAN
parameters must be
less than
64
. If this parameter is not specified, the
default is
23
.
UG-01058
2014.12.19
ALTFP_ADD_SUB Parameters
5-7
ALTFP_ADD_SUB IP Core
Altera Corporation