Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An analog-to-digital converter includes a delta-sigma modulator (10), having the output thereof filtered by a digital filter section. The digital filter section includes a first fixed decimation filter (12) followed by a variable decimation filter section (14) and an output low-pass filter section (16), having a fixed decimation ratio. The fixed variable decimation filter section (14) includes a single FIR filter (24) that has data processed therethrough with different sampling rates. A recursive controller (26) receives an external configuration input to determine the number of passes through the filter (24) that are required to provide the desired decimation ratio.

Abstract: An electrically programmable memory array having rows and columns of floating gate type memory cells employs alternate output lines and ground lines between the columns of cells, providing a virtual ground arrangement. A row is selected by one part of an address input, and a column selected by another part. An output line on one side of the selected column is activated, and a ground line on the other side. A differential sense amplifier is responsive to the voltage on the selected output line and a reference voltage. To speed up the access time of the memory, the ground select is implemented and applied first, then the output of the ground select is used to generate the column select. In this manner, the biasing sequence for the array can begin before the decode of the column select has been completed.

Abstract: An electrically programmable memory array having rows and columns of floating gate type memory cells employs alternate output lines and ground lines between the columns of cells, providing a virtual ground arrangement. A row is selected by one part of an address input, and a column selected by another part. An output line on one side of the selected column is activated, and a ground line on the other side. A differential sense amplifier is responsive to the voltage on the selected output line and a reference voltage. In a programming mode of operation, the application of high voltages to the row and column lines is controlled to prevent programming voltage from reaching a selected column until after all transistors in a row are turned on by programming voltage on a row line. This prevents unwanted programming conditions.

Abstract: An electrically programmable memory array having rows and columns of floating gate type memory cells employs alternate output lines and ground lines between the columns of cells, providing a virtual ground arrangement. A row is selected by one part of an address input, and a column selected by another part. An output line on one side of the selected column is activated, and a ground line on the other side. A differential sense amplifier is responsive to the voltage on the selected output line and a reference voltage. A power down mode of operation is provided in which current flow in various circuits of the device is greatly reduced. To speed up access time in exiting from power down, the reference voltage input to the sense amplifier is shifted during power down then when exiting returns to its operating value according to a time constant.

Abstract: A single-ended array of rows and columns of memory cells of the floating gate EPROM type employs a differential sense circuit for producing a data output voltage. The sense circuit allows the array to be biased independent of the sense operation. A reference voltage is provided for direct comparison to the operating point of the selected column line, producing a differential voltage whose polarity indicates the logic state of the selected cell.