Abstract: 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.

Abstract: Circuitry for interpolating a value based on a first plurality of samples from within a larger second plurality of samples includes storage for the second plurality of samples, including a plurality of sample memories corresponding in number to the first plurality of samples. Adjacent samples in the sample memories correspond to samples in the second plurality of samples that are separated by other samples numbering one less than that number. A first sample address into a first one of the sample memories is derived by dividing a floor of an index by the number. Respective circuitry for each respective other one of the sample memories derives a respective other sample address from the first sample address based on a remainder of dividing the floor of the index by the number. Shifting circuitry outputs selected samples in a second order under control of a value determined by the remainder.

Abstract: Techniques and mechanisms implement a sample rate converter for resampling data, such as audio data. The resampling may be based on a resampling clock. As the frequency of the resampling clock varies (e.g., due to jitter, rate adjustment, etc.), a control loop feedback mechanism can detect the variations and gradually correct the sampling rate of the resampled data.

Abstract: Efficient matrix operations circuitry is based on combining a matrix decomposition and a forward substitution operations to share the same processing overhead. A dual multiplier circuit selectively applies complex multiplication operations to a first and second input vectors for computing a conjugate dot product vector or a non-conjugate dot product vector. The conjugate dot product vector corresponds to the matrix decomposition operation for triangulating an input matrix to generate an element of a triangulated matrix. The non-conjugate dot product vector corresponds to a forward substitution operation for determining an element of a forward substitution vector from the triangulated matrix.

Abstract: Methods, integrated circuits, and computer programs for managing a communication path carrying multiple channels are presented. Each channel includes a first-in first-out (FIFO) queue. In one method, the time difference between the start of a cycle for receiving data in a particular channel and a start of a cycle for transmitting data in the same particular channel is identified. Further, the method includes an operation for buffering arriving data in the communication path. The arriving data is buffered for an amount of time equal to the identified time difference, and the result is delayed data. FIFO registers are loaded from memory, which includes loading FIFO control and status data for a single FIFO queue, where the single FIFO queue is associated with the current channel of the produced delayed data at any time. Additionally, method includes an operation for processing contemporaneously read and write requests for the single FIFO queue using the loaded FIFO registers.

Abstract: Techniques for implementing multipliers using memory blocks in an integrated circuit (IC) are provided. The disclosed techniques may reduce the number of memory blocks required to implement various multiplication operations. A plurality of generated products is normalized. The normalized products are scaled to generate a plurality of scaled products. Scaled products with the least root mean square (RMS) error are identified. The scaled products with the least RMS error are then stored in a plurality of memory blocks in an IC. The scaled products may have a reduced number of bits compared to the plurality of generated products that have not been normalized and scaled.

Abstract: Precise timing information produced by a block average module may be provided to signal processing circuitry. A sample period value generator may produce samples of the input data period values. A progressive block averaging computation may be applied to the generated input data period value samples. The output of the progressive block averaging computation may be used as the precise input sample rate information. The precise input sample rate information may in turn drive a signal processing application. The precision of the clock information may be increased with an increase in startup overhead.