International Business Machines Corporation

Edward F Mark

Kevin B Cornett

Shyam Ramji

Timothy A Schell

Ari Freund

Bella Dubrov

Haggai Eran

Assigning pins to macro-blocks of an Integrated Circuit (IC) chip is described. The macro-block pin assignments are automatically placed using Constraint Programming (CP) techniques to position the pins on the periphery of a macro-block. Bus-ordering and pin-spacing constraints are performed considering all the nets forming the IC design simultaneously. The CP formulation includes modeling detailed and discrete constraints required to achieve an optimal pin-assignment. A stochastic CSP solver is used to define the cost function on search points giving full assignments to all the variables. The macro-block pins are ultimately moved to computed locations.

Constraint programming based method for bus-aware macro-block pin placement in a hierarchical integrated circuit layout

A pick correlation method, comprises the steps of displaying a pick marker on a display screen; directing the pick marker at an image on the display screen, the image comprising at least one line primitive, and the pick marker having a pick window corresponding thereto; subjecting the at least one line primitive to a trivial test, whereby the at least one line primitive can be trivially tested by the trivial test if the at least one line primitive has both of its end-points outside of the same extended edge of the rectangular shaped pick window and, if successfully tested by the trivial test, accepting or rejecting the at least one line primitive in accordance with the results of the trivial test; and if the at least one line primitive cannot be trivially tested, subjecting the at least one line primitive to a non-trivial test which does not require performing floating point operations, and accepting or rejecting the at least one line primitive in accordance with the results of the non-trivial test.

Pick correlation

A method of pick correlation comprises the steps of displaying a pick marker on a display screen; directing the pick marker at an image on the display screen, the image comprising at least one line primitive, and the pick marker having a diamond shaped pick window corresponding thereto; subjecting the line primitive to a trivial test, the trivial test comprising enclosing the diamond shaped pick window in a least enclosing rectangle, wherein the diamond shaped pick window and the rectangle have a common center point, and rejecting the line primitive if the line primitive has both of its end-points outside of the same extended edge of the rectangle; if the line primitive cannot be trivially tested, subjecting the line primitive to a non-trivial test which does not require performing floating point operations, and accepting or rejecting the line primitive in accordance with the results of the non-trivial test; and considering accepted line primitives as being selected for further processing.

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Poughkeepsie, NY, United States of America

Edward F Mark