Dynamic volume control system

An audio signal processor comprising:

• a stereo analog-to-digital converter (ADC) coupled to a signal pathway;
• a digital signal processor coupled to the stereo ADC in the signal pathway and including special-purpose functional processing logic operational upon a signal transmitted on the signal pathway, the special-purpose functional processing logic applying a gain to the signal;
• and
• a stereo digital-to-analog converter (DAC) with volume control circuit coupled to the digital signal processor in the signal pathway, the stereo DAC with volume control circuit including:
• a digital-to-analog converter (DAC) coupled to the digital signal processor in the signal pathway, the DAC converting a digital signal from the digital signal processor into an analog signal, the digital signal processor including a logic for executing a digital signal processing operation operational upon a signal transmitted on the signal pathway, the digital signal processing operating imposing a gain on the signal;
• an attenuator circuit coupled to the digital signal processor in the signal pathway and having a control terminal, the attenuator circuit controlling attenuation of the signal transmitted in the signal pathway according to a control signal at the control terminal;
• and
• a volume control circuit coupled to the digital signal processor and coupled to the attenuator circuit, the volume control circuit being coupled to receive a user volume signal and including a difference circuit for determining a difference between the gain and the user volume signal, a logic for determining an overall gain signal based on a maximum difference signal of the differences between gain and user volume in a plurality of signal channels, and a logic for determining a new volume signal based on the user volume minus the gain plus the overall gain signal, the new volume signal being coupled to the control terminal of the attenuator circuit and controlling the volume as the control signal.

An audio signal processor according to claim I1, wherein:

• the volume control circuit includes:
• a difference circuit coupled to the digital signal processor to receive the gain and coupled to a user volume control port, the difference circuit determining the difference between the gain and the user volume signal;
• a new volume register coupled to the difference circuit and holding the difference as a new volume;
• an old volume register;
• a counter having a first input terminal coupled to the new volume register and having a second input terminal coupled to the old volume register, the counter decrementing or incrementing a volume depending on the relative amplitude of data in the new volume register and the old volume register, the counter having an output terminal supplying the volume to the old volume register and to the attenuator circuit controlling attenuation of the signal transmitted in the signal pathway.

A method of controlling volume in an audio system comprising:

• executing a digital signal processing operation applied to an audio signal in a plurality of audio signal channels;
• generating a digital signal processing gain signal for each channel of the plurality of audio signal channels;
• receiving a user volume signal for each channel of the plurality of audio signal channels;
• calculating a delta volume signal for each channel of the plurality of audio signal channels, the delta volume signal being equal to the digital signal processing gain signal minus the user volume signal for each channel of the audio signal channels;
• determining an overall gain signal equal to the maximum delta volume signal for the plurality of audio signal channels and having a minimum delta value of zero;
• determining a new volume signal for each channel of the plurality of audio signal channels, the new volume signal being equal to the user volume signal for a channel minus the digital signal processing gain signal for the channel plus the overall gain signal;
• and
• attenuating the audio signal for each channel of the plurality of channels as a function of the new volume signal.

A volume control system comprising:

• a digital signal processor generating a digital signal processor gain;
• a gain buffer coupled to the digital signal processor, the gain buffer storing a plurality of digital signal processor gain signals;
• a user volume buffer storing a plurality of user volume signals;
• a new volume decoder coupled to the gain buffer and coupled to the user volume buffer, the new volume decoder including a difference circuit determining a difference between a digital signal processor gain signal and a user volume signal;
• a new volume register coupled to the new volume decoder, the new volume register holding the difference between a digital signal processor gain signal and a user volume signal;
• and
• an analog and digital volume decoder for decoding a volume signal as a function of the difference between a digital signal processor gain signal and a user volume signal, the volume signal controlling an audio signal in an audio signal path.

A system comprising:

• a volume control system including:
• a digital signal processor generating a digital signal processor gain;
• a gain buffer coupled to the digital signal processor, the gain buffer storing a plurality of digital signal processor gain signals;
• a user volume buffer storing a plurality of user volume signals;
• a new volume decoder coupled to the gain buffer and coupled to the user volume buffer, the new volume decoder including a difference circuit determining a difference between a digital signal processor gain signal and a user volume signal;
• a new volume register coupled to the new volume decoder, the new volume register holding the difference between a digital signal processor gain signal and a user volume signal;
• and
• an analog and digital volume decoder for decoding a volume signal as a function of the difference between a digital signal processor gain signal and a user volume signal, the volume signal controlling an audio signal in an audio signal path;
• a control device coupled to the audio signal processor;
• an audio input device coupled to the audio signal processor;
• and
• a sound production device coupled to the audio signal processor.

A system comprising:

• an audio signal processor including:
• a stereo analog-to-digital converter (ADC) coupled to a signal pathway;
• a digital signal processor coupled to the stereo ADC in the signal pathway and including special-purpose functional processing logic operational upon a signal transmitted on the signal pathway, the special-purpose functional processing logic applying a gain to the signal;
• and
• a stereo digital-to-analog converter (DAC) with volume control circuit coupled to the digital signal processor in the signal pathway, the stereo DAC with volume control circuit including:
• a digital-to-analog converter (DAC) coupled to the digital signal processor in the signal pathway, the DAC converting a digital signal from the digital signal processor into an analog signal, the digital signal processor including a logic for executing a digital signal processing operation operational upon a signal transmitted on the signal pathway, the digital signal processing operating imposing a gain on the signal;
• an attenuator circuit coupled to the digital signal processor in the signal pathway and having a control terminal, the attenuator circuit controlling attenuation of the signal transmitted in the signal pathway according to a control signal at the control terminal;
• and
• a volume control circuit coupled to the digital signal processor and coupled to the attenuator circuit, the volume control circuit being coupled to receive a user volume signal and including a difference circuit for determining a difference between the gain and the user volume signal, a logic for determining an overall gain signal based on a maximum difference signal of the differences between gain and user volume in a plurality of signal channels, and a logic for determining a new volume signal based on the user volume minus the gain plus the overall gain signal, the new volume signal being coupled to the control terminal of the attenuator circuit and controlling the volume as the control signal;
• a control device coupled to the audio signal processor;
• an audio input device coupled to the audio signal processor;
• and
• a sound production device coupled to the audio signal processor.