Xilinx, Inc.

James L McManus

David P Schultz

Scott O Frake

Wilson Kaming Yee

James L Burnham

Eric J Crabill

An apparatus and method for enabling hot swapping of programmable logic devices (PLDs) and boards containing PLDs is provided. If the hot swap capability is desired, a hot swap terminal on the PLD is set to facilitate a floating state on the input/output pad of the PLD. Further, the input buffer and the output buffer of the PLD are disabled. In one embodiment, a predetermined voltage is provided on the output terminal of the input buffer. In this configuration, the hot swap circuit eliminates any leakage current, ensures no static current occurs, and provides appropriate signals to the internal circuits of the PLD.

Method and system for PLD swapping

A core for a register-based programmable logic device includes a register configured to provide a hidden identifier in response to a secret unlock operation. The identifier is inaccessible during normal operation of the core implementation. The unlock operation is selected to be an action or set of actions that would typically not be performed during normal use of the core implementation. The logic associated with providing the hidden identifier in response to the unlock operation is configured to not interfere with normal operation of the core implementation. Therefore, the presence of this source identification capability is transparent to regular users (and unauthorized copyists) of the core implementation. The availability of the secondary identifier can be limited in duration to minimize the chances of accidental, or even intentional, discovery.

Growing community of inventors

Longmont, CO, United States of America

James L McManus