Vector Constant - 2022.1 English

Vitis Model Composer User Guide (UG1483)

Document ID
Release Date
2022.1 English

The Vector Constant Block generates vector constant values.


Super Sample Rate (SSR): This configurable GUI parameter is primarily used to control processing of multiple data samples on every sample period. This block enables 1-D vector data support for the primary block operation.

The Vector Constant block generates a constant that can be a fixed-point value, a Boolean value, or a DSP48 instruction. This block is similar to the Simulink® Vector Constant block, but can be used to directly drive the inputs on HDL blocks.

Block Parameters

Open the Block Parameters dialog box by double-clicking the icon in your Simulink model.

Basic tab

Parameters specific to the Basic tab are as follows:

Constant Value

Specifies the value of the constant. When changed, the new value appears on the block icon. If the constant data type is specified as fixed-point and cannot be expressed exactly in the specified fixed-point type, its value is rounded and saturated as needed. A positive value is implemented as an unsigned number, a negative value as signed.

Output Type
Specifies the data type of the output.
  • Boolean
  • Fixed-point
  • Floating-point
Arithmetic Type
If the Output Type is specified as Fixed-point.
  • Signed (2’s comp)
  • Unsigned
  • DSP48 instruction
Fixed-point Precision
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.
Floating-point Precision
Specifies single precision (32 bits).
Specifies double precision (64 bits).
Activates the field below so you can specify the Exponent width and the Fraction width.
Exponent width
Specifies the exponent width.
Fraction width
Specifies the fraction width.
Sample Period
Sampled Constant
Allows a sample period to be associated with the constant output and inherited by blocks that the constant block drives. (This is useful mainly because the blocks eventually target hardware and the Simulink sample periods are used to establish hardware clock periods.)

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