Atmel Corporation

Ian Fullerton

Frode Milch Pedersen

Sebastien Jouin

Morten Werner Lund

Benjamin Francis Froemming

Sylvain Garnier

Martin Olsson

Yong Luo

Xavier Leprevost

Joseph Martinez

In an embodiment, a method comprises: obtaining a virtual bus address; translating the virtual bus address to a physical address of a portion of NVM storing first data; determining that the first portion of NVM has been allocated previously; reading the first data from the first portion of NVM; determining whether writing second data to the first portion of the NVM would change one or more bits in the first data; responsive to the determining that a write operation only changes data bits in the first data from 1 to 0, writing the second data over the first data stored in the first portion of NVM; and responsive to the determining that one or more bits in the first data would be flipped from 0 to 1, reallocating the first portion of NVM to a second portion of NVM, copying the first data from the first portion of NVM to the second portion of NVM with the first data modified by the second data.

Memory emulation mechanism

The disclosed embodiments provide security extensions for memory (e.g., non-volatile memory) by means of address and data scrambling and differential data storage to minimize exposure to side channel attacks and obfuscate the stored data. The scrambling function maximizes reverse engineering costs when recovering sequences of secret keys.

Security extensions for non-volatile memory

Systems and methods for multi-protocol serial communication interfaces are described. One example system includes an interface module including a buffer for storing a protocol selection. The system includes a protocol module coupled to the interface module and configured for providing one or more serial communication protocols. Based on the protocol selection, one of the serial communication protocols is selected. The system also includes a serial engine module coupled to the interface module and the protocol module. The serial engine module is configured for transmitting and receiving data or commands based on the selected serial communication protocol.

Multi-protocol serial communication interface

A latch signal is received from a non-volatile memory device that is indicative of a current access time for the non-volatile memory device. The access time represents an amount of time required for the non-volatile memory device to make data available responsive to a request for data. A bus system clock signal is received. The latch signal is evaluated and a wait state for the non-volatile memory device is adjusted based on the evaluation. The wait state represents a number of cycles of the bus system clock used by a central processing unit for an access of the non-volatile memory device. A bus system data ready signal that is triggered based on the adjusted wait state is produced. The bus system data ready signal, when triggered, indicates that data is available responsive to the request.

Managing wait states for memory access

A circuit is disclosed that provides a programmable hold time for a bus signal without running a system clock and without a frequency requirement between the system clock and a bus clock.

Programmable bus signal hold time without system clock

A detector circuit is disclosed that detects bus signal conditions. To detect a START condition, asynchronous sequential logic detects a first bus signal transition (e.g., from high to low) and a second bus signal (e.g., a high signal). The outputs of the asynchronous sequential logic are combined to produce a START signal that can be latched, so that the START signal can be used to wake up a system or for other purposes. To detect a STOP condition, asynchronous sequential logic is set by a transition (e.g., low to high) of the first bus signal and a second bus signal (e.g., a high signal), producing a STOP signal that can be used to reset the asynchronous sequential logic and the latch.

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Los Gatos, CA, United States of America

Ian Fullerton