Patent application number | Description | Published |
20090060228 | Systems and Methods for Shadowing an HDA Codec - Systems and methods for “shadowing” a target codec to provide additional features that are not available in the target codec. In one embodiment, an audio amplification system includes a High Definition Audio (HDA) bus, and an HDA controller, a conventional HDA codec and a shadow HDA codec coupled to the HDA bus. The conventional codec receives audio data and commands from the HDA controller via the bus and processes them to generate an output audio signal. The shadow codec snoops the audio data and commands on the HDA bus that are targeted to the conventional codec. The shadow codec processes the snooped audio data and commands to generate a second audio output. The shadow codec does not communicate with the HDA controller and is transparent to the controller. The shadow codec does not request enumeration from the HDA controller and does not receive an address from the HDA controller. | 03-05-2009 |
20090062948 | Systems and Methods for Controlling Audio Volume in the Processor of a High Definition Audio Codec - Systems and methods for controlling the audio volume of an audio signal in an HDA codec having a programmable processor such as a DSP, wherein the codec receives digital audio signals and audio volume control verbs over an HDA bus, and the audio volume levels associated with the audio volume control verbs are used by the processor in the generation pulse width modulated (PWM) output signals, thereby controlling the audio volume levels of the output signals. The processor may be configured to adjust non-volume parameters such as PWM deadtime, in addition to adjusting audio volume, based on the audio volume levels. The codec may be implemented in a PC or other system that implements an HDA system that includes the HDA bus and HDA codec. | 03-05-2009 |
20090063738 | Systems and Methods for Overriding Hardwired Responses in an HDA Codec - Systems and methods for overriding hardwired responses of a codec to High Definition Audio (HDA) verbs that are received from an HDA controller. In one embodiment, an HDA codec is configured to store one or more overriding responses, each of which is associated with a corresponding HDA verb. When an HDA verb is received by the codec, the codec determines whether the verb is associated with one of the overriding responses. If the verb is associated with one of the overriding responses, the overriding response is returned to the HDA controller. If the first HDA verb is not associated with one of the stored overriding responses, provide a hardwired response associated with the first HDA verb to the HDA bus. Overriding responses can be returned for unsupported verbs only, or for any verbs that prompt responses. | 03-05-2009 |
20090063828 | Systems and Methods for Communication between a PC Application and the DSP in a HDA Audio Codec - Systems and methods implemented in a PC for enabling communication between an application executing on the CPU and a DSP that is incorporated into a codec in the High Definition Audio (HDA) system, wherein the communication is carried out via the HDA bus. In one embodiment, an HDA codec includes one or more conventional HDA widgets coupled to a programmable processor such as a DSP. The codec includes a set of registers that are configured to store HDA verbs and data transmitted via the HDA bus. The programmable processor is configured to identify verbs that indicate associated information is a communication from an application executing on the CPU, read the associated information, and process the information according to the associated verbs. The information may be program instructions, parametric data, requests for information, etc. | 03-05-2009 |
20090063843 | Systems and Methods for Booting a Codec Processor over a High Definition Audio Bus - Systems and methods for booting a programmable processor such as a DSP that is incorporated into an HDA codec. The codec and a system memory containing boot program instructions are connected to an HDA bus. In a first mode, the DSP receives boot program instructions via the HDA bus and boots using these instructions. In a second mode, the DSP boots from instructions that are contained in a memory that is connected to the DSP. In one embodiment, the memory connected to the DSP is a component of a plug-in card, and the DSP is configured to determine whether the plug-in card is present, then boot from the memory on the plug-in card if it is present or boot from the system memory via the HDA bus if the plug-in card is not present. | 03-05-2009 |
Patent application number | Description | Published |
20080278230 | Systems and Methods for Correcting Errors Resulting from Component Mismatch in a Feedback Path - Systems and methods for minimizing performance degradation due to component mismatch in the feedback path of a digital PWM amplifier feedback loop. One embodiment comprises a digital pulse width modulated (PWM) amplifier with feedback. The amplification subsystem receives a digital audio signal and produces an analog output signal. The feedback loop produces a feedback signal based on the filtered analog output signal and modifies the digital audio signal based on the feedback signal. The feedback loop includes a filter configured to filter the analog output signal and correction circuitry configured to correct component mismatch errors introduced by the filter. In one embodiment, the correction circuitry receives a measurement of a power supply voltage, multiplies the measured voltage by a gain and adds the scaled measurement to the feedback signal to correct for the component mismatch errors. | 11-13-2008 |
20090027117 | Low-Noise, Low-Distortion Digital PWM Amplifier - Systems and methods for performance improvements in digital switching amplifiers using low-pass filtering to reduce noise and distortion. In one embodiment, a digital pulse width modulation (PWM) amplifier includes a signal processing plant configured to receive and process an input audio signal. The amplifier also includes a low-pass filter configured to filter audio signals output by the plant. The filtered output of the plant is added to the input audio signal as feedback. The plant may consist of a modulator and power switch, a noise shaper, or any other type of plant. An analog-to-digital converter (ADC) may be provided to convert the output audio signal to a digital signal. Filtering may be implemented before or after the ADC, and a decimator may be placed after the ADC if it is an oversampling ADC. | 01-29-2009 |
20090027118 | Digital PWM Amplifier Having a Low Delay Corrector - Systems and methods for performance improvements in digital switching amplifiers using a low delay corrector. In one embodiment, a digital pulse width modulation (PWM) amplifier includes a signal processing plant configured to receive and process an input audio signal. The amplifier also includes a low delay corrector configured to receive signals output by the plant. The output of the low delay corrector is added to the input audio signal as feedback. The plant may consist of a modulator and power switch, a noise shaper, or any other type of plant. An analog-to-digital converter (ADC) may be provided to convert the output audio signal to a digital signal. Filtering may be implemented before or after the ADC, and a decimator may be placed after the ADC if it is an oversampling ADC. | 01-29-2009 |
20090143884 | SYSTEMS AND METHODS FOR SAMPLE RATE CONVERSION - Systems and methods are provided for converting input data streams having variable input sample rates to an output sample rate, which systems and methods are used in processing the data streams. In one embodiment, a system includes a clock source, a counter configured to count cycles for a corresponding data stream, and a data processor. The data processor is configured to read the number of cycles counted by the counter between received frame sync signals and to convert the first data stream to the predetermined output sample rate based on the corresponding number of cycles counted. | 06-04-2009 |
20090302938 | LOW DELAY CORRECTOR - A low delay corrector (LDC) unit includes a non-linear function generator and a filter. The nonlinear function generator receives a first signal and outputs a second signal in dependence on the first signal and a transfer function of the nonlinear function generator. The filter is fed in dependence on the second signal output by the nonlinear function generator. The first signal received by the nonlinear function generator is derived in dependence on an input signal provided to an input of the LDC unit and an output of the filter. An output of the LDC unit is derived in dependence on the first signal received by the nonlinear function generator and the second signal output by the nonlinear function generator. | 12-10-2009 |