Allow design delay distribution

Whether to allow distributed pipelining and delay absorption optimizations to move design delays

Renamed from Preserve design delays in R2023b

Model Configuration Pane: Optimization / Pipelining

Description

The Allow design delay distribution parameter specifies whether to allow distributed pipelining and delay absorption optimizations to move design delays in your model.

Settings

On (default) | Off

On

Allow distributed pipelining and delay absorption to move or absorb design delays in the model.

Off

Prevent distributed pipelining and delay absorption from moving or absorbing design delays in the model.

Tips

To set this property, use the functions hdlset_param or makehdl. To view the property value, use the function hdlget_param.

For example, suppose you have a model named sfir_fixed that contains a subsystem named symmetric_fir. To enable this parameter programmatically, use one of these methods:

• Pass the property as an argument to the makehdl function.

  makehdl('sfir_fixed/symmetric_fir', ... 
          'AllowDelayDistribution','off')

• Use hdlset_param to disable the parameter on the model and then generate HDL code using makehdl.

  hdlset_param('sfir_fixed','AllowDelayDistribution','off')
  makehdl('sfir_fixed/symmetric_fir')

Recommended Settings

No recommendations.

Programmatic Use

Parameter: AllowDelayDistribution

Type: character vector

Value: 'on' | 'off'

Default: 'on'

Version History

Introduced in R2014a

R2023b: Renamed from Preserve design delays

The Preserve design delays parameter, which you programmatically set using PreserveDesignDelays, is now Allow design delay distribution.

In R2023a and earlier, the default for Preserve design delays was off. From R2023b, the default for Allow design delay distribution is on.

R2023b: Controls delay absorption

Previously, this parameter only affected distributed pipelining. In R2023b, this parameter controls both distributed pipelining and delay absorption.

If you set Preserve design delays to on in a model created in R2023a or earlier, HDL Coder™ prevented distributed pipelining from moving design delays. If you set Preserve design delays to off, the parameter is now on and also prevents delay absorption.