Abstract: A processor including instruction support for implementing the Kasumi block cipher algorithm may issue, for execution, programmer-selectable instructions from a defined instruction set architecture (ISA). The processor may include a cryptographic unit that may receive instructions for execution. The instructions include one or more Kasumi instructions defined within the ISA. In addition, the Kasumi instructions may be executable by the cryptographic unit to implement portions of a Kasumi cipher that is compliant with 3rd Generation Partnership Project (3GPP) Technical Specification TS 35.202 version 8.0.0. In response to receiving a Kasumi FL( )-operation instruction defined within the ISA, the cryptographic unit may perform an FL( ) operation, as defined by the Kasumi cipher, upon a data input operand and a subkey operand in which the data input operand and subkey operand may be specified by the Kasumi FL( )-operation instruction.

Abstract: A processor including instruction support for implementing the Data Encryption Standard (DES) block cipher algorithm may issue, for execution, programmer-selectable instructions from a defined instruction set architecture (ISA). The processor may include a cryptographic unit that may receive instructions for execution. The instructions include one or more DES instructions defined within the ISA. In addition, the DES instructions may be executable by the cryptographic unit to implement portions of an DES cipher that is compliant with Federal Information Processing Standards Publication 46-3 (FIPS 46-3). In response to receiving a DES key expansion instruction defined within the ISA, the cryptographic unit may generate one or more expanded cipher keys of the DES cipher key schedule from an input key.

Abstract: A processor including instruction support for implementing the Advanced Encryption Standard (AES) block cipher algorithm may issue, for execution, programmer-selectable instructions from a defined instruction set architecture (ISA). The processor may include a cryptographic unit that may receive instructions for execution. The instructions include one or more AES instructions defined within the ISA. In addition, the AES instructions may be executable by the cryptographic unit to implement portions of an AES cipher that is compliant with Federal Information Processing Standards Publication 197 (FIPS 197). In response to receiving a first AES encryption round instruction defined within the ISA, the cryptographic unit may perform an encryption round of the AES cipher on a first group of columns of cipher state having a plurality of rows and columns. A maximum number of columns included in the first group may be fewer than all of the columns of the cipher state.

Abstract: A floating-point circuit may include a floating-point operand normalization circuit configured to receive input floating-point operands of a given floating-point divide operation, the operands comprising a dividend and a divisor, as well as a divide engine coupled to the normalization circuit. In response to determining that one or more of the input floating-point operands is a denormal number, the operand normalization circuit may be further configured to normalize the one or more of the input floating-point operands and output a normalized dividend and normalized divisor to the divide engine, and dependent upon respective numbers of leading zeros of the dividend and divisor prior to normalization, generate a value indicative of a maximum possible number of digits of a quotient (NDQ). The divide engine may be configured to iteratively generate NDQ digits of a floating-point quotient from the normalized dividend and the normalized divisor provided by the floating-point operand normalization circuit.

Abstract: Systems and methods for enabling on-chip features via efuses. A system comprises an electronic fuse (Efuse) array (EFA) coupled to each features capability register (FCR) within an instantiated computational block. The EFA comprises a plurality of rows wherein programming an row comprises blowing one or more Efuses of the row. A valid row comprises programmed Efuses corresponding to one or more on-chip enabled features. The EFA is further configured to prevent enabling of disabled on-chip features from occurring subsequent to a predetermined point in time, such as the time of shipping the chip to the field for use by end-users, by establishing a particular default state for electronic fuses and rendering unusable any unprogrammed entries of the EFA. In one embodiment, some features correspond to on-chip hardware cryptographic acceleration.

Abstract: An apparatus and method for implementing a hash algorithm word buffer. In one embodiment, a cryptographic unit may include hash logic configured to compute a hash value of a data block according to a hash algorithm, where the hash algorithm includes a plurality of iterations, and where the data block includes a plurality of data words. The cryptographic unit may further include a word buffer comprising a plurality of data word positions and configured to store the data block during computing by the hash logic, where subsequent to the hash logic computing one of the iterations of the hash algorithm, the word buffer is further configured to linearly shift the data block by one or more data word positions according to the hash algorithm. The hash algorithm may be dynamically selectable from a plurality of hash algorithms.

Abstract: An apparatus and method for cryptographic key expansion. According to a first embodiment, a cryptographic unit may include key storage configured to store an expanded set of cipher keys for a cipher algorithm, and a key expansion pipeline comprising a plurality of pipeline stages. During a key expansion mode of operation, each pipeline stage may be configured to perform a corresponding step of generating a member of the expanded set of cipher keys according to a key expansion algorithm. During a cipher mode of operation, a portion of the key expansion pipeline may be configured to perform a step of the cipher algorithm.

Abstract: An apparatus and method for implementing a unified hash algorithm pipeline. In one embodiment, a cryptographic unit may include hash logic configured to compute a hash value of a data block according to a hash algorithm, where the hash algorithm is dynamically selectable from a plurality of hash algorithms, and where the hash logic comprises a plurality of pipeline stages each configured to compute a portion of the hash algorithm. The cryptographic unit may further include a word buffer configured to store the data block during computing by the hash logic.

Abstract: A processor including general-purpose and cryptographic functionality, in which cryptographic operations are visible to user-specified software. According to one embodiment, a processor may include instruction execution logic configured to execute instructions specified by a user of the processor, where the instructions are compliant with a general-purpose instruction set architecture. The processor may further include a cryptographic functional unit configured to implement a plurality of cryptographic operations, and further configured to process the cryptographic operations independently of the instruction execution logic. A subset of the instructions may be executable to cause individual ones of the cryptographic operations to be processed by the cryptographic functional unit.

Abstract: Implementing an unfused multiply-add instruction within a fused multiply-add pipeline. The system may include an aligner having an input for receiving an addition term, a multiplier tree having two inputs for receiving a first value and a second value for multiplication, and a first carry save adder (CSA), wherein the first CSA may receive partial products from the multiplier tree and an aligned addition term from the aligner. The system may include a fused/unfused multiply add (FUMA) block which may receive the first partial product, the second partial product, and the aligned addition term, wherein the first partial product and the second partial product are not truncated. The FUMA block may perform an unfused multiply add operation or a fused multiply add operation using the first partial product, the second partial product, and the aligned addition term, e.g., depending on an opcode or mode bit.

Abstract: An apparatus and method for implementing a block cipher algorithm. In one embodiment, a cryptographic unit configured to implement a block cipher algorithm may include state storage configured to store cipher state, where the cipher state includes a plurality of rows and a plurality of columns. The cryptographic unit may further include a cipher pipeline comprising a plurality of pipeline stages, where each pipeline stage is configured to perform a corresponding step of the block cipher algorithm on the cipher state, and where a given one of the pipeline stages is configured to concurrently process fewer than all of the columns of the cipher state.

Abstract: A method and apparatus for implementing out-of-order memory transactions in a multithreaded, multicore processor. In the present invention, circular queue comprising a plurality of queue buffers is used to store load data returned by a memory unit in response to a request issued by a processing module, such as a stream processing unit, in a processing core. As requests are issued, a destination queue buffer ID tag is transmitted as part of the request. When the request is returned, that destination number is reflected back and is used to control which queue within the circular queue will be used to store the retuned load data. Separate pointers are used to indicate the order of the queues to be read and the order of the queues to be written. The method and apparatus implemented by the present invention allows out-of-order data to be processed efficiently, thereby improving the performance of a fine grain multithreaded, multi-core processor.

Abstract: A method and device divides a dividend by a divisor, the dividend and the divisor both being integers. The method and device determine a maximum possible number of quotient digits (NDQ) based on a number of significant digits of the divisor and the dividend, normalizes the dividend and divisor, and calculates NDQ number of quotient digits from the normalized divisor and dividend.

Abstract: A method and apparatus for controlling power consumption in a multi-threaded processor. In one embodiment, the processor includes at least one logic unit for processing instructions. The logic unit includes a plurality of positions, wherein each of the plurality of positions corresponds to at least one instruction thread. Clock signals may be provided to the logic unit via a clock gating unit. The clock gating unit is configured to inhibit a clock signal from being provided to a corresponding one of the thread positions when no instruction thread is active for that position. The inhibiting of the clock signal for an inactive thread position may reduce power consumption by the processor.

Abstract: In one embodiment, a processor comprises a first register file configured to store speculative register state, a second register file configured to store committed register state, a check circuit and a control unit. The first register file is protected by a first error protection scheme and the second register file is protected by a second error protection scheme. A check circuit is coupled to receive a value and corresponding one or more check bits read from the first register file to be committed to the second register file in response to the processor selecting a first instruction to be committed. The check circuit is configured to detect an error in the value responsive to the value and the check bits. Coupled to the check circuit, the control unit is configured to cause reexecution of the first instruction responsive to the error detected by the check circuit.

Abstract: An apparatus and method to support pipelining of variable-latency instructions in a multithreaded processor. In one embodiment, a processor may include instruction fetch logic configured to issue a first and a second instruction from different ones of a plurality of threads during successive cycles. The processor may also include first and second execution units respectively configured to execute shorter-latency and longer-latency instructions and to respectively write shorter-latency or longer-latency instruction results to a result write port during a first or second writeback stage. The first writeback stage may occur a fewer number of cycles after instruction issue than the second writeback stage. The instruction fetch logic may be further configured to guarantee result write port access by the second execution unit during the second writeback stage by preventing the shorter-latency instruction from issuing during a cycle for which the first writeback stage collides with the second writeback stage.

Abstract: An execution unit adapted to perform at least a portion of the Data Encryption Standard. The execution unit includes a Left Half input; a Key input; and a Table input. The execution unit also includes a first group of transistors configured to receive the Table input, perform a table look-up, and output data. The execution unit further includes a first exclusive-or operator having two inputs and an output. The first exclusive-or operator is configured to receive the Left Half input and the Key input. The execution unit also includes a second exclusive-or operator having two inputs and an output. The second exclusive-or operator is configured to receive the data output by the first group of transistors and to receive the output of the first exclusive-or operator. The execution unit also includes a third exclusive-or operator having two inputs and an output. The third exclusive-or operator is configured to receive the Left Half input and the data output by the first group of transistors.

Abstract: An execution unit adapted to perform at least a portion of the Data Encryption Standard. The execution unit includes a Left Half input; a Key input; and a Table input. The execution unit also includes a first group of transistors configured to receive the Table input, perform a table look-up, and output data. The execution unit further includes a first exclusive-or operator having two inputs and an output. The first exclusive-or operator is configured to receive the Left Half input and the Key input. The execution unit also includes a second exclusive-or operator having two inputs and an output. The second exclusive-or operator is configured to receive the data output by the first group of transistors and to receive the output of the first exclusive-or operator. The execution unit also includes a third exclusive-or operator having two inputs and an output. The third exclusive-or operator is configured to receive the Left Half input and the data output by the first group of transistors.

Abstract: An apparatus and method for floating-point special case handling. In one embodiment, a processor may include a first execution unit configured to execute a longer-latency floating-point instruction, and a second execution unit configured to execute a shorter-latency floating-point instruction. In response to the longer-latency floating-point instruction being issued to the first execution unit, the second execution unit may be further configured to detect whether a result of the longer-latency floating-point instruction is determinable from one or more operands of the longer-latency floating-point instruction independently of the first execution unit executing the longer-latency floating-point instruction. In response to detecting that the result is determinable, the second execution unit may be further configured to flush the longer-latency floating-point instruction from the first execution unit and to determine the result.

Abstract: A processor employing synchronization primitives for flexible scheduling of functional unit operations. In one embodiment, a processor may include a number of functional units, each configured to retrieve operations for processing from an operation storage, and where each functional unit is configured to process retrieved operations independently of each other functional unit. The processor may further include instruction fetch logic configured to issue instructions for execution by the processor, where a subset of the instructions are executable to store operations for processing by the functional units into the operation storage. The operations stored by the subset of the instructions may include synchronization operations configured to coordinate processing of other ones of the operations by the plurality of functional units. In one particular implementation of the processor, the synchronization operations may include a suspend operation and a resume operation.