Patent ID: 7818584
Filing Date: 2010-10-19
Classification: G06F,H04L

Abstract:
1. A method of preventing an unauthorized access of an integrated circuit, the method comprising: receiving information at a first circuit of the integrated circuit, providing the information to a memory on the integrated circuit; asserting a write enable signal for the memory using a second circuit; writing the information to the memory at a first input of the memory; and then permanently preventing the memory from receiving, at a second input, another write enable signal after the information is stored in the memory, wherein the information is an encoding key used to de code an encrypted configuration bitstream for configuring an integrated circuit, and wherein permanently preventing the memory from receiving another write enable signal is accomplished by disabling the second circuit, determining whether the second circuit is disabled, and if the second circuit is disabled, then reading the key from the memory; else preventing the integrated circuit from being configured using the encrypted configuration bitstream.