Tapped Delay Enabled Synchronous

Delay scalar signal multiple sample periods and output all delayed versions when external Enable signal is true

Since R2023a

Libraries:
HDL Coder / Discrete

Description

The Tapped Delay Enabled Synchronous block delays an input by the specified number of sample periods. The block returns output signal for each delay when the external Enable signal E is true.

For example, when you specify Number of delays as 4 and Order output starting with as Oldest, the block returns four signals, the first delayed by four sample periods, the second delayed by three, and so on. Use this block to discretize a signal in time domain or resample a signal.

Output Vector Order

The block accepts one scalar input and generates an output vector that contains data for each incremental delay. Specify the order of the delayed signals in the output vector with the Order output vector starting with parameter:

Oldest orders the output vector starting with the oldest delay version and ending with the newest delay version.
Newest orders the output vector starting with the newest delay version and ending with the oldest delay version.

Specify the output vector for the first sampling period with the Initial condition parameter. Careful selection of this parameter can mitigate unwanted output behavior.

Synchronous State Control

The block uses synchronous state control semantics. When you use this block in your model and generate HDL code by using HDL Coder™, your model generates cleaner HDL code and uses fewer hardware resources due to the Synchronous behavior of the block.

Examples

Simulate and Generate HDL Code for Tapped Delay Enabled Resettable Synchronous Block

Implement the Tapped Delay Enabled Resettable Synchronous block in a Simulink® model that a delays scalar signal multiple sample periods and output all delayed versions when external Enable signal is true and external Reset signal is false. You also generate HDL code for the model.

Open Script

Limitations

The block does not support vector inputs on the Enable port.
You cannot use the block inside Enabled Subsystem, Triggered Subsystem, or Resettable Subsystem blocks that use Classic semantics. The Subsystem must use Synchronous semantics.

Ports

Input

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u — Input signal
scalar

Input signal to delay.

E — Enable signal
`Scalar`

The block accepts the Enable signal of the data types listed below. For more information, see Data Types Supported by Simulink.

When the Enable signal is false, the state and output signal hold the previous value. The Enable signal is true when E input is not zero and false when E input is zero.

Output

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y — Delayed versions of input signal
scalar | vector

All versions of the delayed input signal. Use the Order output vector starting with parameter to specify the order of delayed signals in the output vector.

Parameters

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Initial condition — Initial output
`0.0` (default) | scalar

Specify the initial output of the simulation. The Initial condition parameter is converted from a double to the input data type offline using round-to-nearest and saturation.

Limitations

The initial condition of this block cannot be inf or NaN.

Programmatic Use

Block Parameter: vinit

Type: character vector

Values: scalar

Default: '0.0'

Sample time — Time between samples
`-1` (default) | scalar | vector

Specify the time interval between samples. To inherit the sample time, set this parameter to -1. For more information, see Specify Sample Time.

Programmatic Use

Block Parameter: samptime

Type: character vector

Values: scalar | vector

Default: '-1'

Number of delays — Number of discrete-time operators
`4` (default) | positive scalar | `-1` (for inherited)

Specify the number of discrete-time operators as a positive scalar, or -1 for inherited.

A value of -1 instructs the block to inherit the number of delays by backpropagation. Each delay is equivalent to the z^-1 discrete-time operator, which the Unit Delay block represents.

Programmatic Use

Block Parameter: NumDelays

Type: character vector

Values: positive scalar | -1 (inherited)

Default: '4'

Order output vector starting with — Order of output
`Oldest` (default) | `Newest`

Specify whether to output the oldest delay version first, or the newest delay version first.

Programmatic Use

Block Parameter: DelayOrder

Type: character vector

Values: 'Oldest' | 'Newest'

Default: 'Oldest'

Include current input in output vector — Include current input in output vector
`off` (default) | `on`

Select this check box to include the current input in the output vector.

Programmatic Use

Block Parameter: includeCurrent

Type: character vector

Values: 'off' | 'on'

Default: 'off'

Extended Capabilities

HDL Code Generation
Generate VHDL, Verilog and SystemVerilog code for FPGA and ASIC designs using HDL Coder™.

HDL Coder provides additional configuration options that affect HDL implementation and synthesized logic.

HDL Architecture

This block has one default HDL architecture.

HDL Block Properties

ConstrainedOutputPipeline	Number of registers to place at the outputs by moving existing delays within your design. Distributed pipelining does not redistribute these registers. The default is `0`. For more details, see ConstrainedOutputPipeline.
InputPipeline	Number of input pipeline stages to insert in the generated code. Distributed pipelining and constrained output pipelining can move these registers. The default is `0`. For more details, see InputPipeline.
OutputPipeline	Number of output pipeline stages to insert in the generated code. Distributed pipelining and constrained output pipelining can move these registers. The default is `0`. For more details, see OutputPipeline.
ResetType	Suppress reset logic generation. The default is `default`, which generates reset logic. See also ResetType.

Complex Data Support

This block supports code generation for complex signals.

Version History

Introduced in R2023a

Tapped Delay Enabled Synchronous

Description

Examples

Simulate and Generate HDL Code for Tapped Delay Enabled Resettable Synchronous Block

Limitations

Ports

Input

u — Input signal scalar

E — Enable signal Scalar

Output

y — Delayed versions of input signal scalar | vector

Parameters

Initial condition — Initial output 0.0 (default) | scalar

Limitations

Programmatic Use

Sample time — Time between samples -1 (default) | scalar | vector

Programmatic Use

Number of delays — Number of discrete-time operators 4 (default) | positive scalar | -1 (for inherited)

Programmatic Use

Order output vector starting with — Order of output Oldest (default) | Newest

Programmatic Use

Include current input in output vector — Include current input in output vector off (default) | on

Programmatic Use

Extended Capabilities

HDL Code Generation Generate VHDL, Verilog and SystemVerilog code for FPGA and ASIC designs using HDL Coder™.

Version History

See Also

u — Input signal
scalar

E — Enable signal
`Scalar`

y — Delayed versions of input signal
scalar | vector

Initial condition — Initial output
`0.0` (default) | scalar

Sample time — Time between samples
`-1` (default) | scalar | vector

Number of delays — Number of discrete-time operators
`4` (default) | positive scalar | `-1` (for inherited)

Order output vector starting with — Order of output
`Oldest` (default) | `Newest`

Include current input in output vector — Include current input in output vector
`off` (default) | `on`

HDL Code Generation
Generate VHDL, Verilog and SystemVerilog code for FPGA and ASIC designs using HDL Coder™.