FixPt Constant (Fixed-Point Blockset)

Generate a constant value

Description

The FixPt Constant block is a masked S-function that generates a constant value.

You specify constants with the Constant value parameter. A constant can be a scalar or a vector.

You specify the output scaling with the Output scaling parameter. Note that there are two dialog box parameters that control the output scaling: one associated with an edit field, and one associated with a parameter list. If Output data type is a generalized fixed-point number such as sfix(16), the Output scaling parameter list provides you with these scaling modes:

Use Specified Scaling - This mode uses the slope/bias or radix point-only scaling specified for the editable Output scaling parameter (for example, 2^-10).

Best Precision: Vector-wise - This mode produces a common radix point for each element of the Constant value vector based on the best precision for the largest value of the vector.

For a detailed description of all other block parameters, refer to Block Parameters.

Parameters and Dialog Box

Constant value: Constant value output by the block. It can be a scalar or vector. All members of the output vector must be the same data type.
Output data type and scaling: Specify the output data type and scaling via the dialog box, or inherit the data type and scaling via back propagation.
Output data type: Any data type supported by the Fixed-Point Blockset.
Output scaling: Radix point-only or slope/bias scaling. Additionally, if Constant value is specified as a vector, it can be scaled using the constant vector scaling modes for maximizing precision. These scaling modes are available only for generalized fixed-point data types.
Override data type(s) with doubles: If checked, Output data type is overridden with doubles.

Conversions

The Constant value parameter is converted from a double to the specified output data type offline using round-to-nearest and saturation. Refer to Parameter Conversions for more information about parameter conversions.

Characteristics

Output Port
Any data type supported by the blockset

Direct Feedthrough
No

Sample Time
Inherited

Scalar Expansion
No - the output is always the same size as Constant value

States
0

Vectorized
Yes

Output Port	Any data type supported by the blockset
Direct Feedthrough	No
Sample Time	Inherited
Scalar Expansion	No - the output is always the same size as Constant value
States	0
Vectorized	Yes

FixPt Bitwise Operator FixPt Conversion