Abstract: In a parallel computer system having N parallel computing units a data pipeline connects all the computing units. In addition the computing units are coupled to a random access memory so that each computing unit is assigned to one column of the memory array. To perform a digital signal processing filter operation the required coefficients are stored in the memory so that one or more different filter operations can be carried out in an interleaved way.

Abstract: With reference to FIG. 1 signal processor (10) for performing transformations of sets of input data points comprises a memory for storing a first half input data points and a second half input data points, an adder unit for pairwise adding one real part of each one first half input data point and a second half input data point and providing adder output data, and a computing unit for performing transformations upon the adder output data. Addition for data reduction and data transformation are carried out simultaneously by different units.

Abstract: Parallel signal processor (10) (FIG. 2) performs a Fourier Transformation of an input signal; The transformation coefficients are converted once to logarithmic form and stored in a cache memory. The input data is converted serially to logarithmic form, and fed to all processing units in parallel. The processing units compute their respective products as additions in the logarithmic domain. Then, the products are converted back to the normal domain. The products with the correct sign are summed by an accumulator of the respective processing element. After the last signal data point has run through the processing elements and the last products are added to their respective sums, all complex output signal data points are complete simultaneously.

Abstract: An encoding system (400) receives samples and coefficients from a bus (422). The system comprises a plurality of parallel operating memory devices (430-k), registers (435-k), computing units (440-k), and accumulator units (460-k). The system (400) further comprises a parallel-to-serial buffer (470) coupled to the accumulator units (440-k) and a pair generator (480) for providing amplitude/index pairs. The system (400) performs encoding steps such as transforming, quantizing, zigzagging, rate controlling, and run-length coding. Transforming is explained for the example of a Forward Discrete Cosine Transformation (FDCT). According to a method (500) of the present invention, zigzagging (510) occurs prior to transforming (570) and performed only once when transformation coefficients are provided to the memory devices (430-k) in a zigzag arrangement. Quantizing occurs prior to transforming by pre-calculating the coefficients with quantizers.

Abstract: A parallel computer processor that performs L1 norm calculations includes a plurality of processing elements and a data pipeline which couples the processing elements. The data vectors for which the L1 norm is to be calculated are stored in storage lines of a cache memory. In operation each processing element accesses data in its private storage column in the cache memory and calculates a term signal. The term signals are added to form the resulting L1 norm.

Abstract: A pulse width modulator (20) includes a reconfigurable counter (30) whose width is determined by mode control bits. In one embodiment, a decoder (24) decodes the mode control bits to provide decoded width control signals to the reconfigurable counter (30). The width control signals enable selected least significant counter cells (101-107) of the reconfigurable counter (30) in a binary-to-thermometer fashion. Thus, unused counter cells are disabled, reducing power. The pulse width modulator (20) also includes an output circuit (25) which provides a pulse width modulated output signal having a duty cycle determined by a proportion of a cycle of the reconfigurable counter (30) during which a comparator (23) detects that an output of the reconfigurable counter (30) has reached a value of an input number. A portion of the comparator (23) may also be disabled in response to the width control signals.

Abstract: A pulse width modulator (PWM) (20) receives a two's complement input number and separates a sign bit from remaining less significant bits. The PWM converts these bits into an unsigned number in dependence on the sign bit. A comparator (41) provides a compare output signal in response to an output of a counter (30) equaling the unsigned number. An output circuit (25) provides first and second pulse width modulated signals for a length of time determined by the output of the comparator (41) in dependence on whether the sign bit indicates a positive or negative sign. In one embodiment, the PWM (20) converts a negative two's complement number to the unsigned number by one's complementing the least significant bits, and the output circuit (25) keeps the second pulse width modulated signal active for one additional clock cycle to fully convert to two's complement form, without the need for a carry operation.