# Documentation

### This is machine translation

Translated by
Mouseover text to see original. Click the button below to return to the English version of the page.

# Discrete Impulse

Generate discrete impulse

## Library

Sources

`dspsrcs4`

## Description

The Discrete Impulse block generates an impulse (the value `1`) at output sample `D+1`, where `D` is specified by the Delay parameter (`D``0`). All output samples preceding and following sample `D+1` are zero.

When `D` is a length-N vector, the block generates an M-by-N matrix output representing N distinct channels, where frame size M is specified by the Samples per frame parameter. The impulse for the `i`th channel appears at sample `D(i)+1`.

The Sample time parameter value, Ts, specifies the output signal sample period. The resulting frame period is M*Ts.

## Examples

Construct the model below.

Configure the Discrete Impulse block to generate a three-channel output of type `double`, with impulses at samples 1, 4, and 6 of channels 1, 2, and 3, respectively. Use a sample period of 0.25 and a frame size of 4. The corresponding settings should be as follows:

• Delay = `[0 3 5]`

• Sample time = `0.25`

• Samples per frame = `4`

• Output data type = `double`

Run the model and look at the output, `dsp_examples_yout`. The first few samples of each channel are shown below.

```dsp_examples_yout(1:10,:) ans = 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 ```

The block generates an impulse at sample 1 of channel 1 (first column), at sample 4 of channel 2 (second column), and at sample 6 of channel 3 (third column).

## Dialog Box

The Main pane of the Discrete Impulse block dialog appears as follows.

Delay

The number of zero-valued output samples, `D`, preceding the impulse. A length-N vector specifies an N-channel output.

Sample time

The sample period, Ts, of the output signal. The output frame period is M*Ts.

Samples per frame

The number of samples, M, in each output frame.

The Data Types pane of the Discrete Impulse block dialog appears as follows.

Output data type

Specify the output data type for this block. You can select one of the following:

• A rule that inherits a data type, for example, ```Inherit: Inherit via back propagation```. When you select this option, the output data type and scaling matches that of the next downstream block.

• A built in data type, such as `double`

• An expression that evaluates to a valid data type, for example, `fixdt(1,16)`

Click the button to display the Data Type Assistant, which helps you set the Output data type parameter.

## Supported Data Types

• Double-precision floating point

• Single-precision floating point

• Fixed point

• Boolean

• 8-, 16-, and 32-bit signed integers

• 8-, 16-, and 32-bit unsigned integers

 Data Type Conversion Simulink Constant Simulink Multiphase Clock DSP System Toolbox N-Sample Enable DSP System Toolbox Signal From Workspace DSP System Toolbox `impz` Signal Processing Toolbox