Lightspeed Semiconductor Corporation

Otrsotech, Limited Liability Company

Lyle Smith

Shridhar K Mukund

Robert Osann, Jr

Eric T West

Shafy Eltoukhy

Eric F Dellinger

Rabi Sengupta

Pat Hom

Steven Eplett

Eric West

Stephen Eplett

Logic blocks for IC designs (including gate-array, standard cell, or logic array designs) provide Design-for-Test-enabled flip-flops (DFT-enabled FFs) that inherently insure compliance with DFT rules associated with scan shifting. Test scan-chains are configured by daisy-chaining instances of the logic block in a transparent (invisible) manner to user-designed application circuits, which can be designed without any user-inserted test structures or other regard for DFT considerations. User asynchronous set and reset inputs and all Stuck-At faults on all user pins on these DFT-enabled FFs are observable via capture and scan-out. A first type of these DFT-enabled FFs features addressable control to partition test the application circuit. A second type of these DFT-enabled FFs features integral capture buffering that eliminates the need for partition test, simplifying control logic and reducing the number of test vectors needed.

Transparent test method and scan flip-flop

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

An embodiment of the invention includes a routing architecture with a plurality of predesigned layers and a custom layer. The structure includes a plurality of parallel vertical tracks. In one layer, the tracks include a pin coupled to an input/output of an underlying function block and the track also includes a first portion of an unbroken conductive path. A second portion of the unbroken conductive path is formed under the pin in at least a second predesigned layer. In some embodiments, the second portion of the unbroken conductive path is formed in the second predesigned layer for some tracks and a third predesigned layer for other tracks. Hence, pins and unbroken conductive paths are multiplexed in a single track. In addition, the second predesigned layer further includes long horizontal conductors. When using the predesigned layers, the custom layer can be structured to provide free global routing with distinct local routing, all while using an array structure independent of routing channels and without rendering any function blocks unusable. Moreover, a structure in accordance with the invention includes conductors for clock distribution which can be used to form multiple independent clock domains. The structure is compact, yet flexible and can be customized in some embodiments with 1-2 masks.

ASIC routing architecture

Programmable logic array embedded in mask-programmed ASIC

Described herein is an ASIC having an array of predesigned function blocks. The function blocks can be used to implement combinational logic, sequential logic, or a combination of both. The function blocks also have a selectable output drive strength. The output drive strength can be selected, in some embodiments, using mask programming.

Function block architecture with variable drive strengths

Growing community of inventors

Menlo Park, CA, United States of America

Lyle Smith