Altera Corporation

Keone Streicher

Martin Langhammer

David Edward Jefferson

Juju Joyce

Yi-Wen Lin

Srinivas T Reddy

Hyun Mo Yi

Nitin Prasad

David Lewis

Volker Mauer

Henry Y Lui

Triet M Nguyen

Suleyman Sirri Demirsoy

Wai-Bor Leung

Kwan Yee Martin Lee

Orang Azgomi

Robert L Pelt

Configurable specialized processing blocks, such as DSP blocks, are described that implement fixed and floating-point functionality in a single mixed architecture on a programmable device. The described architecture reduces the need to construct floating-point functions outside the configurable specialized processing block, thereby minimizing hardware cost and area. The disclosed architecture also introduces pipelining into the DSP block in order to ensure the floating-point multiplication and addition functions remain in synchronicity, thereby increasing the maximum frequency at which the DSP block can operate. Moreover, the disclosed architecture includes logic circuitry to support floating-point exception handling.

Programmable device implementing fixed and floating point functionality in a mixed architecture

Circuits, methods, and apparatus that prevent detection and erasure of encoding or encryption keys. These encoding keys may be used to encode a configuration bitstream or other data for an FPGA or other device. An exemplary embodiment of the present invention masks a first key to form an encoding key in order to prevent detection of the first key. In a specific embodiment, the first key is encoded using a second key. The encoded key is used to encode a configuration bitstream or other data. The encoded key is stored on an FPGA or other device. When the device is to be configured, the encoded key is retrieved and used to decode the bitstream or other data. A further embodiment stores an encryption key in a one-time programmable memory (OTP) array to prevent its erasure or modification. The encoding key may be further obfuscated before storage.

FPGA configuration bitstream protection using multiple keys

Circuits, methods, and apparatus that prevent detection and erasure of a configuration bitstream or other data for an FPGA or other device. An exemplary embodiment of the present invention masks a user key in order to prevent its detection. In a specific embodiment, the user key is masked by software that performs a function on it a first number of times. The result is used to encrypt a configuration bitstream. The user key is also provided to an FPGA or other device, where the function is performed a second number of times and the result stored. When the device is configured, the result is retrieved, the function is performed on it the first number of times less the second number of times and then it is used to decrypt the configuration bitstream. A further embodiment uses a one-time programmable fuse (OTP) array to prevent erasure or modification.

FPGA configuration bitstream encryption using modified key

Digital signal processing ('DSP') circuit blocks are provided that can more easily work together to perform larger (e.g., more complex and/or more arithmetically precise) DSP operations if desired. These DSP blocks may also include redundancy circuitry that facilitates stitching together multiple such blocks despite an inability to use some block (e.g., because of a circuit defect).

Digital signal processing circuitry with redundancy and bidirectional data paths

Digital signal processing ('DSP') circuit blocks are provided that can more easily work together to perform larger (e.g., more complex and/or more arithmetically precise) DSP operations if desired. These DSP blocks may also include redundancy circuitry that facilitates stitching together multiple such blocks despite an inability to use some block (e.g., because of a circuit defect). Systolic registers may be included at various points in the DSP blocks to facilitate use of the blocks to implement systolic form, finite-impulse-response ('FIR'), digital filters.

Modular digital signal processing circuitry with optionally usable, dedicated connections between modules of the circuitry

Circuits, methods, and apparatus that store and prevent modification or erasure of stored encoding keys, serial identification numbers, or other information. An encoding key stored with an embodiment of the present invention may be used to decode a configuration bitstream on an integrated circuit, such as an FPGA. A serial number may be used to track or authenticate an integrated circuit. Embodiments of the present invention store this information in a memory such as an SRAM, DRAM, EPROM, EEPROM, flash, fuse array, or other type of memory. In order to prevent its erasure or modification, write enable circuitry for the memory is then permanently disabled, and if the memory is volatile, a continuous power supply is provided. Further refinements verify that the write enable circuitry has been disabled before allowing the device to be configured or to be operable.

One-time programmable memories for key storage

A specialized processing block for a programmable logic device incorporates a fundamental processing unit that performs a sum of two multiplications, adding the partial products of both multiplications without computing the individual multiplications. Such fundamental processing units consume less area than conventional separate multipliers and adders. The specialized processing block further has input and output stages, as well as a loopback function, to allow the block to be configured for various digital signal processing operations.

Growing community of inventors

San Ramon, CA, United States of America

Keone Streicher