PPA Optimization in Synthesis & Physical Design | Area | VLSI Design

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In VLSI physical design and synthesis, achieving optimal PPA ( Power, Performance, Area)  is of paramount importance. Among these criteria, area efficiency is a critical consideration. EDA tools play a crucial role in optimizing area utilization


Let's looks into various techniques for area optimization:

Auto-Ungrouping & Boundary Optimization:
EDA tools employ auto-ungrouping to strategically break down certain hierarchical structures, benefiting both area and timing. Furthermore, the tools optimize the placement of hierarchical instance boundaries to minimize area usage. It is recommended to keep these settings enabled, unless specific design constraints necessitate otherwise.

Sequential Merging/Removal:
EDA tools perform sequential analysis to identify and eliminate sequencial elements that do not contribute to the generation of output signals. Additionally, these tools identify sequential elements that consistently store identical values and merge them to reduce redundancy, ultimately saving area.

Clock Gating:
Implementing clock gating techniques involves selectively disabling clock signals to unused or idle modules. This minimizes power consumption and, indirectly, reduces area by removing unnecessary logic gates.

Library Cell Choice:
Optimal selection of library cells during synthesis significantly influences the design's area efficiency. By selecting cells with appropriate functionality and size, designers can achieve a balanced compromise between area and performance.

Effort Level and Physical Synthesis:
Adjusting the effort level setting influences the extent of optimization performed during physical synthesis. Higher effort levels typically lead to more aggressive optimizations, potentially yielding greater area savings. Physical synthesis itself involves various transformations that contribute to area reduction.

DRC (Design Rule Check) Fixing Post Timing:
Addressing design rule violations after timing optimization helps ensure the design adheres to fabrication requirements. Fixing DRC issues can involve resizing cells or adjusting placements, indirectly impacting the design's overall area.

Correct Timing Constraints:
Accurate timing constraints play a pivotal role in achieving optimal PPA balance. Over-constraining the design can lead to excessive cell additions, thereby increasing the overall area. Designers should strike a balance between meeting timing goals and minimizing area overhead.

By employing these area optimization techniques, designers can effectively reduce chip area while maintaining or even enhancing power, performance, and speed characteristics. The careful implementation of these strategies ensures that the resulting design strikes a harmonious balance between the various aspects of PPA.

#area #pd #timing #pv #clock #synthesis #infineon #eda #automation

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