Mult - 2020.2 English

Vivado Design Suite Reference Guide: Model-Based DSP Design Using System Generator (UG958)

Document ID
Release Date
2020.2 English

This block is listed in the following Xilinx Blockset libraries: Math, Floating-Point, and Index.

The Xilinx Mult block implements a multiplier. It computes the product of the data on its two input ports, producing the result on its output port.

Block Parameters

The block parameters dialog box can be invoked by double-clicking the icon in your Simulink® model.

Basic tab
Parameters specific to the Basic tab are as follows.

This parameter allows you to specify the output precision for fixed-point arithmetic. Floating point output always has Full precision.

The block uses sufficient precision to represent the result without error.
User Defined
If you do not need full precision, this option allows you to specify a reduced number of total bits and/or fractional bits.
Fixed-point output type
Arithematic Type
Signed (2’s comp)
The output is a Signed (2’s complement) number.
The output is an Unsigned number.
Number of bits
Specifies the bit location of the binary point of the output number, where bit zero is the least significant bit.
Binary point
Position of the binary point in the fixed-point output.

Refer to the Overflow and Quantization section in the Common Options in Block Parameter Dialog Boxes topic.


Refer to the Overflow and Quantization section in the Common Options in Block Parameter Dialog Boxes topic.

Optional Port
Provide enable port
This defines the number of sample periods by which the block's output is delayed.
Note: Only when latency of the Mult block is set to 4 in System Generator, are all three pipeline stages used in the generated Multiplier IP.
Implementation tab
Parameters specific to the Implementation tab are as follows.
Use behavioral HDL (otherwise use core)

The block is implemented using behavioral HDL. This gives the downstream logic synthesis tool maximum freedom to optimize for performance or area.

Note: For Floating-point operations, the block always uses the Floating-point Operator core.
Core Parameters
Optimize for Speed|Area
Directs the block to be optimized for either Speed or Area.
Use embedded multipliers
This field specifies that if possible, use the XtremeDSP slice (DSP48 type embedded multiplier) in the target device.
Test for optimum pipelining
Checks if the Latency provided is at least equal to the optimum pipeline length. Latency values that pass this test imply that the core produced is optimized for speed.

Other parameters used by this block are explained in the topic Common Options in Block Parameter Dialog Boxes.