International Business Machines Corporation

William J Scarpero, Jr

Patrick James Meaney

Jonathan Yang Chen

Kevin Charles Gower

Frank David Ferraiolo

Christopher J Berry

Timothy Gerard McNamara

Robert Walter Berry, Jr

Lawrence D Curley

Philip George Shephard, Iii

Bernd K Koenemann

Gulsun Yasar

Kenneth D Wagner

Glenn E Holmes

Jose Luis Pontes Correia Neves

Travis Wellington Pouarz

David A Kiesling

John W Hartman

Charles W Cha

The process of laying out a floorplan for a clock control distribution network in an integrated chip design is simplified and the efficiency of a staging network created is improved. Rather than manually create the staging network in HDL or as a network description table while looking at a picture of the chip floorplan in a Cadence Viewer, an automated method which runs in the Cadence environment uses an algorithmic approach to the problem of maximizing the utilization of staging latches, eliminating unnecessary power and area usage. Efficiency is maximized by updating the Physical Layout directly with the staging solution arrived at by the algorithm.

Method of automating creation of a clock control distribution network in an integrated circuit floorplan

A method of calibrating an elastic interface is provided to automatically achieve a minimal cycle delay through the interface. An existing self-alignment interface (i.e. elastic interface) is used to de-skew within a cycle and stage the data to have it arrive on a given, programmed target cycle. However, this target cycle must be calculated in advance and may be larger than it needs to be, causing more latency on the interface. This method is used to determine the earliest target cycle (with or without additional guard-band). This target cycle is used to adjust the interface automatically to achieve this earliest target cycle. The determination of earliest target cycle can be done once, continuously, or using a sample window. The method also can be used for interfaces that have frequency multipliers or phase shifts at its boundaries.

Method for receiver delay detection and latency minimization for a source synchronous wave pipelined interface

A method of calibrating an interface is provided to automatically achieve a minimal cycle latency while maintaining synchronous data arrival between a multiplicity of self-aligning interfaces. Independent self-alignment interfaces may de-skew data bits and have them arrive on a minimum cycle boundary. However, if all the interfaces do not arrive on the same cycle, SMP designs may not function properly. For instance, with a single control chip and multiple data chips on an AMP node, the control chip often sends out controls to the dataflow chips. If the data arriving on the elastic interfaces is not synchronized with the controls, the data is not routed properly. The method employs a calibration pattern to determine the latest cycle that data is received across the elastic interfaces and calculates the target cycle for all the interfaces to match this latest cycle. The target cycle is fed back into the design and the data is received synchronously, also provided is a test to ensure that the data arrives synchronously.

Digital system having a multiplicity of self-calibrating interfaces

An exemplary embodiment of the invention is a method and apparatus for configuring system cycle time in a data processing system with at least one master latch clock generating a master latch clock signal and at least one slave latch clock generating a slave latch clock signal. Timing errors are detected during system hardware testing. Adjustments to the system timing are calculated based on error for at least one of a master latch clock signal and a slave latch clock signal. The on-cycle edge of at least one of the master latch clock signal and slave latch clock signal is adjusted based on the calculations while maintaining a corresponding mid-cycle edge of at least one of the master latch clock signal and the slave latch clock signal.

System and method for adjusting timing parts

A memory embedded in a integrated processor chip is dynamically stressed tested by repeatedly writing a test pattern to the data locations of the memory in which a high percentage of the memory cells are sequentially written with complementary data in order to create a high stress on the memory devices. The test pattern is generated as a function of the number of address locations of the memory and the number of data bits of a memory data word. The test pattern is rotated each time the memory is addressed. The test pattern preferably has a contiguous group of digits with the number of digits in the contiguous group being a function of the number of address locations and the number of data bits in the memory word. The memory data input register is configured as a recirculating loop and additional dummy bits are added to provide recirculating loops longer than the data input register. A plurality of independent circulating loops may be created in the data input register or in combination with a number of dummy register bits.

Method and apparatus for memory dynamic burn-in and test

Integrated circuit logic chips often oscillate during testing because the large unbypassed inductance of the test fixture causes off-chip driver switching noise to be fed back to the logic chip power supply. Oscillation may be prevented by adding an inhibit receiver and an off-chip driver inhibit network to the logic chip. The off-chip driver inhibit network provides a fan out path from the inhibit receiver to each off-chip driver. In response to an inhibit signal applied to the inhibit receiver, the inhibit network forces each of the off-chip drivers to the same logical state, the logic state being the natural logic state assumed by the off-chip drivers upon initial application of power to the chip. The driver inhibit receiver and inhibit network are employed to prevent oscillation at chip power-on, during driver and receiver parametric testing and during input test pattern tests.

Oscillation prevention during testing of integrated circuit logic chips

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Poughkeepsie, NY, United States of America

William J Scarpero, Jr