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PLD_MP


PLD_MP Description

PLD_MP is a synthesis constraint. It is useful for making the macro handling independent of design hierarchy processing (see Flatten Hierarchy option). This allows you to merge all hierarchical blocks in the top module, while still keeping the macros as hierarchical modules. You can also keep the design hierarchy except for the macros, which are merged with the surrounded logic. Merging the macros sometimes gives better results for design fitting. Two values are available for this option:

  • YES (check box is checked): macros are preserved and generated by Macro+.
  • NO (check box is not checked): macros are rejected and generated by HDL synthesizer

Depending on the Flatten Hierarchy value, a rejected macro becomes a hierarchical block (Flatten Hierarchy=no) or is merged in the design logic (Flatten Hierarchy=yes). Very small macros (2-bit adders, 4-bit multiplexers) are always merged, independent of the Macro Preserve or Flatten Hierarchy options.

PLD_MP Architecture Support

PLD_MP is supported with all CPLDs.

PLD_MP Applicable Elements

You can apply PLD_MP globally only.

PLD_MP Propagation Rules

Not applicable.

PLD_MP Syntax Examples

ECS Schematic Editor

Not applicable.

VHDL

Not applicable.

Verilog

Not applicable.

ABEL

Not applicable.

NCF

Not applicable.

UCF

Not applicable.

XCF

Not applicable.

Old XST Constraint File

Not applicable.

Constraints Editor

Not applicable.

PCF

Not applicable.

Floorplanner

Not applicable.

PACE

Not applicable.

FPGA Editor

Not applicable.

XST Command Line

Define globally with the -pld_mp command line option of the run command. Following is the basic syntax:

-pld_mp {YES|NO}

The default is YES.

See the "Command Line Mode" chapter in the XST User Guide for details.

Project Navigator

You can define PLD_MP globally with the Macro Preserve option in the Xilinx Specific Options tab of the Process Properties dialog box within the Project Navigator.

With a design selected in the Sources window, right-click Synthesize in the Processes window to access the appropriate Process Properties dialog box.


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