Abstract: Systems and methods for optimizing system performance in variable length decoding systems are described. Embodiments are described in which decode tables are analyzed and elements of the tables sorted by probability of occurrence. Storage of elements can be determined by probability of occurrence and embodiments of the present invention can optimize system efficiency by storing most likely entries into fast-memory and least likely entries in slowest memory. In certain embodiments, a single large table is provided that cannot fit into decoder fast-memory. In some embodiments, individual elements can be optimized for storage in fast-memory by selecting more frequently occurring entries or groups of entries into decoder memory.

Abstract: Methods and systems that leverage the advantages of Huffman coding to increase processing efficiency of a data-stream while simultaneously minimizing storage requirements are provided. Decoding efficiency and table storage requirements can be balanced to produce systems that can be adapted for use in high-end network infrastructure applications and for low-resourced portable consumer devices. The systems and methods are operative in decoding data streams using multi-symbol codes and sign information, including AAC and MP3 data streams. A hierarchical structure of tables is described as having primary tables, secondary tables, tertiary tables and so on. Optimization balances processing requirements, table storage requirements and the described systems and methods may be implemented on a variety of processing platforms.

Abstract: The present invention provides a system and method for introducing white noises into a digital audio signal so that there is progressive and cumulative degradation in audio quality after each successive reproduction of the audio sound signal in a fashion analogous to analog audio reproduction. The invention provides a white noise generator, and a digital entroping unit. In a preferred embodiment, the white noise generator is implemented by a hardware random number generator. The digital entroping unit controls the magnitude of white noise desired based on a random number generated by the random number generator, and adds the white noise to the input audio sound signal to produce a degraded audio sound signal. The magnitude of white noise can be controlled by using various masking and formatting of random number data.

Abstract: A system and method are disclosed for controlling the frequency of a common clock which is shared by a plurality of processing elements. The usage of the common clock by each of the plurality of processing elements is measured, and the common clock is controlled to have a frequency determined as a function of the measured common clock usage by the plurality of processing elements.

Abstract: A power management system and method permit the total power consumption by a portable electronic device to be reduced so that the portable electronic device has a longer operating time on a limited power source, such as a battery. The system may also be used with devices that are powered by a more permanent source of power. The system may combine static power management techniques as well as dynamic power management techniques. The system may include a flexible clock generator.

Abstract: An interrupt handling system and method for a multiple processor system permit the interrupts generated by one or more hardware devices to be routed and prioritized dynamically. In particular, the interrupt controller permits the interrupts to be dynamically routed between the multiple processors and permits a particular interrupt to be dynamically assigned a priority level. The interrupt handling system also permits software based interrupts wherein, for example, one processor may interrupt another processor.

Abstract: To facilitate inter-processor communication between multiple processors in a computer system and to enable the accessing of a dual port memory, or other system resources, without requiring the memory or the data/address bus to be locked, the present invention provides a semaphore unit that preferably incorporates a shared mailbox architecture that, in combination with a set of hardware semaphore registers, enables inter-process communication among the multi-processors. Cooperative multitasking may be accomplished through the use of shared mailbox communication protocols while a preemptive multitasking may be accomplished through the use of hardware semaphore registers.

Abstract: The present invention provides a vector floating point unit (FPU) comprising a product-terms bus, a summation bus, a plurality of FIFO (first in first out) registers, a crossbar operand multiplexor coupled, a floating point multiplier, and a floating point adder. The floating point multiplier and the floating point adder are disposed between the crossbar operand multiplexor and the product-terms and summation buses, and are in parallel to each other. The invention also provides the configuration register and the command register in order to provide flexible architecture and the capability to fine-tune the performance to a particular application. The invention performs the multiplication operation and the addition operation in a pipelined fashion. Once the pipeline is filled, the invention outputs one multiplication output and one addition output at each clock cycle.

Abstract: A piece of media, apparatus and method are provided wherein the piece of media may store the audio data as well as equalizer settings that permit the audio data to be equalized. In one embodiment, the piece of media stores equalized audio data and the equalizer settings. In accordance with the invention, in one embodiment, the equalizer-effect piece of media permits the audio data on the piece of media to be equalized even when the audio data player does not include an equalizer. In another embodiment, the equalizer-effect piece of media includes raw audio data and equalizer settings and permits an external equalizer to play equalized audio data without needing to set the equalizer. In a preferred embodiment, the piece of media may be compact disk.

Abstract: A random number generation system and method use the randomness in hardware circuitry start-up to generate a random seed for a random number. In a preferred embodiment, the instability of a phase locked loop is used.

Abstract: A filter system and method are provided that is particular applicable to the resampling of a signal, such as a digital audio signal. The filtering method in accordance with the invention may use a nearest neighbor strategy to reduce the complexity and cost of the filter without reducing the precision of the resampling.