A method includes converting, by n analog to digital converter circuits, n analog signals into n first digital signals having a first data rate frequency; converting, by n digital decimation filtering circuits, the n first digital signals into n second digital signals having a second data rate frequency; and converting, by n digital bandpass filter (BPF) circuits, the n second digital signals into a plurality of outbound digital signals having a third data rate frequency. The coefficients for the taps of a digital BPF circuit is set to produce a bandpass region approximately centered at the oscillation frequency of the analog signal and having a bandwidth tuned for filtering a pure tone component of the analog signal. The first data rate frequency is a first integer multiple of the third data rate frequency. The second data rate frequency is a second integer multiple of the third data rate frequency.

A method is provided that includes performing, by a processor in response to a vector finite impulse response (VFIR) filter instruction, generating of a plurality of filter outputs using a plurality of coefficients and a plurality of sequential data elements, the plurality of coefficients specified by a coefficient operand of the VFIR filter instruction and the plurality of sequential data elements specified by a data operand of the VFIR filter instruction, and storing the filter outputs in a storage location specified by the VFIR filter instruction.

Decimation filter circuitry may include polyphase filtering structures that perform decimation filtering using filter coefficients. Generic polyphase filtering structures do not take advantage of symmetries between the corresponding filter coefficients. If desired, the arrangement of the polyphase filtering structures in the decimation filter circuitry may be optimized relative to generic polyphase filtering structures to take advantage of corresponding filter coefficient symmetries, thereby allowing for implementation of dynamic decimation ratios and a dynamic number of channels while reducing the number of required multipliers by half with respect to generic polyphase filters. Decimation filters may include pre-adder circuitry that receives first and second portions of a data stream and adds corresponding samples from the first and second portions to generate pre-added values. Convolving circuitry may generate filtered output data by convolving the pre-added values with corresponding filter coefficients based on symmetry of the filter coefficients.

Methods and devices are described for reducing the audible effect of pre-responses in an audio signal. The pre-responses are effectively delayed by employing a digital non-minimum-phase filter, which includes a zero lying outside the unit circle in its z-transform response. This zero is not paired with another zero at a reciprocal position inside the unit circle, as this would linearise the phase modification. The filtering can introduce a greater group delay at the pre-response frequency than at a low frequency, such as 500 Hz or even 0 Hz. The technique can be used to reduce pre-responses in an existing audio signal and also to pre-empt pre-responses that would be introduced to the audio signal by subsequent processing.

In a method of operating a computer system, an instruction loop is executed by a processor in which each iteration of the instruction loop accesses a current data vector and an associated current vector predicate. The instruction loop is repeated when the current vector predicate indicates the current data vector contains at least one valid data element and the instruction loop is exited when the current vector predicate indicates the current data vector contains no valid data elements.

A method is provided that includes receiving, in a permute network, a plurality of data elements for a vector instruction from a streaming engine, and mapping, by the permute network, the plurality of data elements to vector locations for execution of the vector instruction by a vector functional unit in a vector data path of a processor.

A method is provided that includes performing, by a processor in response to a floating point multiply instruction, multiplication of floating point numbers, wherein determination of values of implied bits of leading bit encoded mantissas of the floating point numbers is performed in parallel with multiplication of the encoded mantissas, and storing, by the processor, a result of the floating point multiply instruction in a storage location indicated by the floating point multiply instruction.

A method includes converting, by n analog to digital converter circuits, n analog signals into n first digital signals having a first data rate frequency; converting, by n digital decimation filtering circuits, the n first digital signals into n second digital signals having a second data rate frequency; and converting, by n digital bandpass filter (BPF) circuits, the n second digital signals into a plurality of outbound digital signals having a third data rate frequency. The coefficients for the taps of a digital BPF circuit is set to produce a bandpass region approximately centered at the oscillation frequency of the analog signal and having a bandwidth tuned for filtering a pure tone component of the analog signal. The first data rate frequency is a first integer multiple of the third data rate frequency. The second data rate frequency is a second integer multiple of the third data rate frequency.

A polyphase decimation FIR filter apparatus including a modulo integrator circuit configured to integrate input samples and to provide integrated input samples; and a polyphase FIR filter circuit configured to process the integrated input samples, the polyphase FIR filter circuit including a plurality of multiplier accumulator circuits, each configured to accumulate products of coefficients and respective integrated signal samples, wherein each of the multiplier accumulator circuits receives a subset of FIR filter coefficients, wherein the FIR filter coefficients are derived as the nth difference of original filter coefficients, where n is a number of integrators in the integrator circuit, and wherein the FIR filter circuit is configured to perform computation operations with modulo arithmetic.

A method is provided that includes receiving, in a permute network, a plurality of data elements for a vector instruction from a streaming engine, and mapping, by the permute network, the plurality of data elements to vector locations for execution of the vector instruction by a vector functional unit in a vector data path of a processor.