Abstract: In one embodiment, a DSP having four arithmetic logic units (ALUs) and able to have two read/write operations per clock cycle performs silence detection and tone detection for data frames containing samples of an audio signal. The ALUs are used together in parallel to process the samples in the data frames received by the DSP. A received data frame is filtered by the silence detection so that substantially silent frames are dropped and non-silent frames are further processed. In the tone detection, a filtered data frame is processed, four samples at a time, to determine the power of the signal at a given frequency, where the power determination is used to determine whether a given tone (i.e., a signal at a given frequency) is present in the data frame.

Abstract: An adaptive filter configured to use multiple algorithm species that differ in the quality of echo suppression and respective burdens imposed on the computational resources of the host communication device. Depending on the available computational budget, the adaptive filter selects an algorithm species that, while supporting a relatively high quality of echo suppression, involves a relatively low risk of overwhelming the computational resources. The adaptive filter monitors changes in the available computational budget and, if appropriate or necessary, can change the algorithm species to maintain a quality of echo suppression that is optimal for the current computational budget. If a change of the algorithm species is initiated, then at least a portion of internal algorithm data from the previously running algorithm species might be transferred for use in the subsequent algorithm species.

Abstract: In certain embodiments, a digital signal processor (DSP) has multiple arithmetic logic units and a register module. The DSP is adapted to generate a message digest H from a message M in accordance with the SHA-1 standard, where M includes N blocks M(i), i=1, . . . , N, and the processing of each block M(i) includes t iterations of processing words of message schedule {Wt}. In each iteration possible, the DSP uses free operations to precalculate Wt and working variable values for use in the next iteration. In addition, in each iteration possible, the DSP rotates the registers associated with particular working variables to reduce operations that merely copy unchanged values from one register to another.

Abstract: In certain embodiments, a digital signal processor (DSP) has multiple arithmetic logic units and a register module. The DSP is adapted to generate a message digest H from a message M in accordance with the SHA-1 standard, where M includes N blocks M(i), i=1, . . . , N, and the processing of each block M(i) includes t iterations of processing words of message schedule {Wt}. In each iteration possible, the DSP uses free operations to precalculate Wt and working variable values for use in the next iteration. In addition, in each iteration possible, the DSP rotates the registers associated with particular working variables to reduce operations that merely copy unchanged values from one register to another.

Abstract: In one embodiment, a DSP having four arithmetic logic units (ALUs) and able to have two read/write operations per clock cycle performs silence detection and tone detection for data frames containing samples of an audio signal. The ALUs are used together in parallel to process the samples in the data frames received by the DSP. A received data frame is filtered by the silence detection so that substantially silent frames are dropped and non-silent frames are further processed. In the tone detection, a filtered data frame is processed, four samples at a time, to determine the power of the signal at a given frequency, where the power determination is used to determine whether a given tone (i.e., a signal at a given frequency) is present in the data frame.

Abstract: An adaptive filter configured to use multiple algorithm species that differ in the quality of echo suppression and respective burdens imposed on the computational resources of the host communication device. Depending on the available computational budget, the adaptive filter selects an algorithm species that, while supporting a relatively high quality of echo suppression, involves a relatively low risk of overwhelming the computational resources. The adaptive filter monitors changes in the available computational budget and, if appropriate or necessary, can change the algorithm species to maintain a quality of echo suppression that is optimal for the current computational budget. If a change of the algorithm species is initiated, then at least a portion of internal algorithm data from the previously running algorithm species might be transferred for use in the subsequent algorithm species.