.. _MULTIPLIER_MODULE:

MULTIPLIER_MODULE
-------------

This parameter controls what type of multiplier is instantiated by LegUp when
a multiplication operation is used in the program. 
When the "inline" parameter is used, LegUp will print out the "*" operator in 
Verilog. 
When the "generic" parameter is used, LegUp will instantiate a generic multiplier
module that is parameterized for input/output bitwidths and the number of pipeline
stages. 

Caveat 1: When the "inline" parameter is used, and the multiplication operation
is set to take 1 or more cycles (with the set_operation_latency multiply parameter), 
some FPGA synthesis tools may not be able to utilize the internal registers of a
DSP block, which can negatively affect the resulting Fmax. 

Caveat 2: The generic multiplier module does not yet support stalls.

Category
+++++++++

HLS Constraints

Value Type
+++++++++++

String

Valid Values
+++++++++++++

inline, generic

Default Value
++++++++++++++

inline

Location Where Default is Specified
+++++++++++++++++++++++++++++++++++

``examples/legup.tcl``

Dependencies
+++++++++++++

None

Applicable Flows
+++++++++++++++++

All devices and flows

Test Status
++++++++++++

Actively in-use 

Examples
+++++++++

    ``set_parameter MULTIPLIER_MODULE "inline"``
    ``set_parameter MULTIPLIER_MODULE "generic"``

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