Altera Integer Arithmetic IP - Manual (Page 37)

Parameter Name Type Required Description
MAXIMIZE_SPEED
Integer No Altera-specific parameter. You must use
the
LPM_HINT
parameter to specify the
MAXIMIZE_SPEED
parameter in VHDL
design files. You can specify a value
between
0
and
10
. If used, the Quartus II
software attempts to optimize a specific
instance of the LPM_MULT function for
speed rather than area, and overrides the
setting of the Optimization Technique
logic option. If
MAXIMIZE_SPEED
is unused,
the value of the Optimization Technique
option is used instead. For a
SIGNED
multiplier with no inputs being a constant,
if the setting for
MAXIMIZE_SPEED
is
9
-
10
,
the Compiler optimizes the LPM_MULT
megafunction for larger area. These
settings are for backward compatibility
only. If the setting is between
6
-
8
, the
Compiler optimizes for larger area and
higher speed. If the setting is between
1
-
5
,
the Compiler optimizes for smaller area
and high speed. If the setting is
0
, the
smallest and, generally, slowest design
results. For designs with
LPM_WIDTHB
parameters that are
non-power-of-2
, the
default setting is
1
-
5
. For designs with
LPM_WIDTHB
parameters that are a
power-
of-2
, the default value is
6
-
8
. For an
UNSIGNED
multiplier with no inputs being a
constant, if the setting for
MAXIMIZE_
SPEED
is
6
or higher, the Compiler
optimizes for larger area and higher speed.
If the setting is
0
up to
5
, which is the
default value, the Compiler optimizes for
smaller area. Note that specifying a value
for
MAXIMIZE_SPEED
has an effect only if
LPM_REPRESENTATION
is set to
SIGNED
.
DEDICATED_MULTIPLIER_CIRCUITRY
String No Specifies whether to use the default
dedicated multiplier circuitry implementa‐
tion. Values are
AUTO
,
YES
,
NO
, and
FIRM
. If
omitted, the default value is
AUTO
. For
Stratix and Stratix GX devices, the value of
AUTO
specifies that the Quartus II software
determines whether to use the dedicated
multiplier circuitry based on the multiplier
width. If a device does not have dedicated
multiplier circuitry, the
DEDICATED_
MULTIPLIER_CIRCUITRY
parameter has no
effect and the value defaults to
NO
.
4-6 LPM_MULT Parameters
UG-01063
2014.12.19
Altera Corporation LPM_MULT (Multiplier)
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