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 one embodiment, a cryptography processor compatible with the Advanced Encryption Standard (AES) for encrypting and decrypting has a memory storing each element of an AES State, normally 8-bit long, in a corresponding memory space that is at least 9 bits long. Using the larger memory spaces, the processor performs modified AES transformations on the State. A modified column-mixing transformation uses bit-shifting and XOR operations, thereby avoiding some multiplications and modulo reductions and resulting in some 9-bit State elements. A modified byte-substitution transformation uses a 512-element look-up table to accommodate 9-bit inputs. The modified byte-substitution transformation is combined with a modified row-shifting transformation. The memory has data registers each holding four State elements.

Abstract: In one embodiment, a cryptography processor compatible with the Advanced Encryption Standard (AES) for encrypting and decrypting has a memory storing each element of an AES State, normally 8-bit long, in a corresponding memory space that is at least 9 bits long. Using the larger memory spaces, the processor performs modified AES transformations on the State. A modified column-mixing transformation uses bit-shifting and XOR operations, thereby avoiding some multiplications and modulo reductions and resulting in some 9-bit State elements. A modified byte-substitution transformation uses a 512-element look-up table to accommodate 9-bit inputs. The modified byte-substitution transformation is combined with a modified row-shifting transformation. The memory has data registers each holding four State elements.

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.