Broadcom Corporation

Timothy Martin Dobson

Mark Taunton

Sophie Wilson

Alexander J Burr

A system and method for parallelization of saturated accumulation is provided. In the method, an input sequence is divided into a plurality of subsequences. For each subsequence, three parallel saturating additions are performed. The local saturation minimum is the saturating addition of the global saturation minimum and the values of the subsequence. The local midpoint is the saturating addition of the values of the subsequence and the local saturation maximum is the saturating addition of the global saturation maximum and the values of the subsequence. In embodiments, the accumulation total for a subsequence is calculated as the saturating addition of the accumulation total for prior subsequences and the local midpoint of the current subsequence, wherein the accumulation total of the last subsequence is the result of the saturated accumulation for the sequence. In another embodiment, the saturated addition of subsequence results are further parallelized before the final result is reached.

System and method for the parallelization of saturated accumulation operations

A method is used that substantially simultaneously trellis encodes data to be modulated onto multiple tones. The embodiments of the present invention comprise the steps of: (a) using a first input operand comprising state bits for a first trellis stage; (b) using a second input operand comprising a plurality of input data bits; and (c) generating an output comprising output data bits and output state bits from a first or later trellis stage.

DSL trellis encoding

Systems and methods for implementing a zero overhead loop in a microprocessor or microprocessor based system/chip are disclosed. The systems and methods include the use of a breakpoint mechanism, and modification of parameters at runtime, with the breakpoint mechanism being additionally used in debugging, in order to provide some of the looping functionality.

System and method for implementing and utilizing a zero overhead loop

Systems and methods for implementing a zero overhead loop in a microprocessor or microprocessor based system/chip are disclosed. The systems and methods include the use of a breakpoint mechanism which is additionally used in debugging in order to provide some of the looping functionality.

System and method for implementing a zero overhead loop

A method and apparatus are disclosed for efficiently scrambling one or more bytes of data according to DSL standards on a processor. This is achieved by providing an instruction for scrambling one or more bytes of data according to the DSL standards. Accordingly, the invention advantageously provides a processor with the ability to scramble data with a single instruction thus allowing for more efficient and faster scrambling operations for subsequent modulation and transmission.

Single instruction for data scrambling

An embodiment of the present invention provides a system for implementing a Reed-Solomon computation of parity bytes of a codeword, including an accumulator and a logic circuit. The accumulator is configured to hold a plurality of bits. In an embodiment, each bit held in the accumulator initially corresponds to a bit associated with a data byte of the codeword. In another embodiment, each bit held in the accumulator initially correspond to a fixed value. The logic circuit is configured to iteratively compute a new bit for each bit held in the accumulator. After a last iteration of the computation, the bits held in the accumulator correspond to the parity bytes, wherein for each bit held in the accumulator each iteration of the computation comprises computing an exclusive-OR of a fixed subset of bits held in the accumulator. In an embodiment, the exclusive-OR is computed for the fixed subset of bits held in the accumulator and an input bit of the codeword.

System and method for performing reed-solomon encoding

A method and apparatus are disclosed for efficiently bit-reversing and scrambling one or more bytes of payload data according to DSL standards on a processor. In one embodiment, this is achieved by providing an instruction for bit reversing and scrambling one or more bytes of data according to the DSL standards. Accordingly, the invention advantageously provides a processor with the ability to bit reverse and scramble data with a single instruction thus allowing for more efficient and faster scrambling operations for subsequent modulation and transmission.

System and method for bit-reversing and scrambling payload bytes in an asynchronous transfer mode cell

A method and apparatus are disclosed for efficiently de-scrambling one or more bytes of data according to DSL standards on a processor. This is achieved by providing an instruction for de-scrambling one or more bytes of data according to the DSL standards. Accordingly, the invention advantageously provides a processor with the ability to de-scramble data with a single instruction thus allowing for more efficient and faster de-scrambling operations for subsequent processing.

Data de-scrambler

A method and apparatus are disclosed for efficiently de-scrambling and bit-order-reversing one or more bytes of data according to DSL standards on a processor. In a preferred embodiment, this is achieved by providing an instruction for de-scrambling and bit-order-reversing one or more bytes of data according to DSL standards. Accordingly, the invention advantageously provides a processor with the ability to de-scramble and bit-order-reverse data with a single instruction thus allowing for more efficient and faster de-scrambling operations for subsequent processing.

System and method for de-scrambling and bit-order-reversing payload bytes in an Asynchronous Transfer Mode cell

In an Asynchronous Transfer Mode cell, a method and apparatus are disclosed for producing a cell header having bytes with bits in reverse order. Address and control data bytes are received, and a value for a reverse bit Header Error Control byte is generated from the address and control data bytes. Additionally, the order of bits within each address and control data byte is reversed. The produced cell header comprises the reverse bit Header Error Control byte and the address and control data bytes with each address and control data byte having its bits in reversed order. In one embodiment, the present invention provides a processor instruction for producing the cell header having bytes with bits in reverse order. The instruction receives as input address and control data bytes. The instruction then computes a Header Error Control byte and formats the Header Error Control byte in reverse bit order for subsequent processing within the modem. Additionally, the instruction also reverses the bit-order of each byte of the cell header's address and control fields for subsequent processing within the modem.

System and method for generating header error control byte for Asynchronous Transfer Mode cell

An execution unit and method for performing Viterbi decoding is provided. The instruction may be built into an execution unit which executes other instructions, or in its own execution unit. In an example implementation, the instruction is used in implementing the central-office modem (ATU-C) of an asymmetric digital subscriber line ('ADSL') system. In the example implementation, the new instruction takes as input eight input metrics and eight state metrics, and returns as output eight updated state metrics and eight decision bytes. The decision bytes contain: two 'path' bits to enable the previous state to be quickly identified; bits to enable the input bits to be quickly identified; and a carry bit to allow the full value of a state metric to be reconstructed, even though during the calculation only the bottom bits are calculated.

Methods and systems for Viterbi decoding

There is disclosed a technique for accessing a register file which comprises defining a first register address as a plurality of bits and using said first register address to access said register file generating a second register address by using a sequence of said plurality of bits with at least one of said plurality of bits supplied via a unitary operator, the unitary operator being effective to selectively alter the logical value of said bit depending on its logical value in the first register address, and using said second register address to access said register file. A computer system for carrying out such a technique is also enclosed.

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Cambridge, United Kingdom

Timothy Martin Dobson