International Business Machines Corporation

Elmar Gaugler

Wilhelm Ernst Haller

Lukas Daellenbach

Ralf Richter

Friedhelm Kessler

Optimized buffer placement is provided based on timing and capacitance assertions in a functional chip unit including a single source and multiple macros, each having a sink. Placement of the source and macros with the sinks is pre-designed and buffers are placed in branches connecting the source with the multiple sinks. An estimated slack is calculated for each branch, the branches are arranged according to the calculated slack, decoupling buffers are inserted in all branches except the most critical branch(es), the most critical branch(es) are globally routed and slew conditions are fixed within this branch, and at least one next branch is globally routed and slew conditions are fixed therein.

Optimized buffer placement based on timing and capacitance assertions

The invention relates to a method and a system for repartitioning a formalized hardware description of a hierarchically structured electronic circuit design unit comprising a plurality of macros in terms of latch macros and combinatorial macros. In a first step, each macro is dissected into latch macros and signal cones in such a way that

Method and system for repartitioning a hierarchical circuit design

A method is provided for optimized buffer placement based on timing and capacitance assertions in a functional chip unit including a single source and multiple macros, each having a sink. Placement of the source and macros with the sinks is pre-designed and buffers are placed in branches connecting the source with the multiple sinks. The method includes: calculating an estimated slack for each branch based on cycle reach, calculating a minimum slack for each branch, arranging branches according to the calculated slack to evaluate at least one most critical branch, inserting decoupling buffers in all branches except the most critical branch(es) and placing decoupling buffers close to the source, globally routing the most critical branch(es) and fixing slew conditions within this branch, globally routing at least one subsequent branch as arranged according to the calculated slack and fixing slew conditions within this branch(es), and routing all remaining branches.

The invention relates to a method and a system for repartitioning a formalized hardware description of a hierarchically structured electronic circuit design unit comprising a plurality of macros in terms of latch macros and combinatorial macros. In a first step, each macro is dissected into latch macros and signal cones in such a way that Subsequently, combinatorial macros are created by merging combinatorial signal cones along unit signal paths.

A computerized method, data processing system and computer program product reduce noise for a buffered design of an electronic circuit which was already placed and routed. For all areas between a power stripe and a ground stripe (half bay) in the design, the shapes are divided in different criticality levels. The shapes are rearranged based on their criticality level such that shapes with higher criticality level are placed closer to the stripes than those with lower criticality level.

Early noise detection and noise aware routing in circuit design

The invention relates to a method and a system for placing macros of a multilevel hierarchical description of a design unit on a chip. The method starts off by repartitioning the macro structure of the design unit into a set of latch macros and a set of combinatorial macros. By definition, a combinatorial macro is constructed in such a way that it contains no latches, and a latch macro contains latches and is constructed in such a way that each primary input/output of the latch macro coincides with an input or an output of a latch within said latch macro. After repartitioning the macro structure, the latch macros are synthesized within temporary boundaries and placed on the chip. Subsequently, the combinatorial macros are sequentially placed within a temporary boundary and synthesized one by one.

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Boeblingen, Germany

Elmar Gaugler