Lightspeed Semiconductor Corporation

Shafy Eltoukhy

Robert Osann, Jr

Shridhar K Mukund

Lyle Smith

In accordance with the invention, a method for customizing a one-time configurable integrated circuit to include a multi-time configurable structure is disclosed. Such a method includes, in one embodiment receiving a description of circuit functionality from a user for implementation in the one-time configurable device, where the functionality includes a portion that is designated by the user to be reconfigurable. A method in accordance with an embodiment of the invention then models a reconfigurable structure that has enough capacity to accommodate the designated functionality. Optionally, some embodiments of the invention add in more capacity than is required to implement the designated functionality to allow for future reprogramming. The method then embeds the reconfigurable structure in the one-time configurable device. In certain embodiments, the one-time configurable device can be a mask-programmed MBA, gate array, or standard cell, while the reconfigurable structure is a PLA or modified PLA.

Implementing programmable logic array embedded in mask-programmed ASIC

A system and method in accordance with the invention minimizes the redesign burden in tuning and/or customizing PLLs on ICs. Variable resistors are placed in the PLL in places that facilitate tuning. The variable resistors are formed with a set of at least three contacts, where each contact is in electrical communication with a resistive area. A metal layer is used to form leads to the resistive area, where each lead is formed to be in electrical communication with only a selected subset of contacts from the set. In one embodiment, only the uppermost metal layer used in forming the IC is used to form the leads. Because the uppermost metal layer is utilized, the resistor value can be adjusted simply by selecting the subsets of contacts that are to be in electrical communication with the uppermost metal layer. In this manner, only one metal layer needs to be adjusted in tuning and/or customizing a PLL, rather than having to redesign and re-layout all metal layers and vias in the IC.

One-mask customizable phase-locked loop

Programmable logic array embedded in mask-programmed ASIC

A gate array integrated circuit wafer is formed having M&minus;N generic metal interconnection layers and having performance and/or electrical testing circuits which are operative using only the M&minus;N generic metal interconnection layers. Performance and/or electrical tests are performed after generic fabrication is completed, but before the final customization of the wafers. Wafers are sorted and assigned to performance and/or yield bins based upon the results of the performance and/or electrical tests. In another embodiment, all M layers are deposited prior to performance and/or electrical testing; however, the Mth layer is not etched within the active die area prior to performance and/or electrical testing. Subsequent to binning based upon the test results, the final customization is performed by etching the Mth metal layer.

Methods and apparatuses for binning partially completed integrated circuits based upon test results

A gate array integrated circuit wafer is formed having M-N generic metal interconnection layers and having performance and/or electrical testing circuits which are operative using only the M-N generic metal interconnection layers. The performance and electrical testing circuits are located in the active chip area and/or in the scribe line area between dies on the wafer. Performance and/or electrical tests are performed after generic fabrication is completed, but before the final customization of the wafers. Wafers are sorted and assigned to performance and/or yield bins based upon the results of the performance and/or electrical tests. The contents of different bins are provided to different customers for addition of the final N application specific metal interconnection layers based upon the customer's performance and/or yield requirements. In another embodiment, all M layers are deposited prior to performance and/or electrical testing; however, the Mth layer is not etched within the active die area prior to performance and/or electrical testing. Subsequent to binning based upon the test results, the final customization is performed by etching the Mth metal layer. Further, a programmable gate array integrated circuit which has features for testing and binning for speed and performance grading prior to final personalization or programming on the top layer or layers of interconnecting material is provided.

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Los Gatos, CA, United States of America

Shafy Eltoukhy