Low power audio processor that multiplexes component distribution signals
First Claim
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1. A low power audio processor comprising:
- a bit stream processing unit for bit processing an applied audio stream into a bit processed audio stream and for decoding the bit processed audio stream to have a format conducive to digital signal processing;
a digital signal processing unit for digital signal processing the decoded bit processed audio stream received from the bit stream processing unit to develop a digital signal processed audio stream;
a post processing unit for receiving the digital signal processed audio stream from the digital signal processing unit to develop final audio data;
a host interface unit for interfacing with an external device to provide an audio parallel stream received from the external device to the bit stream processing unit;
a power control unit for determining a power state for each of the bit stream processing unit, the digital signal processing unit and the post processing unit in response to;
(1) a request signal and an acknowledge signal between the digital signal processing unit and the post processing unit, (2) a power down signal, and (3) a source clock, the power control unit outputting a determined power state as a power mode signal; and
an internal clock signal generator unit for receiving the source clock and the power down signal and generating clock signals, each of the clock signals corresponding to a respective one of the bit stream processing unit, the digital signal processing unit and the post processing unit.
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Abstract
A low power audio processor is disclosed which includes: a bit stream processing unit for performing bit processing for an applied audio stream and for decoding the bit processed audio stream to have a format conducive to digital signal processing; a digital signal processing unit for receiving the decoded data from the bit stream processing unit to perform digital signal processing; a post processing unit for post processing audio data from the digital signal processing unit to output final audio data; and a host interface unit for interfacing with an external device to provide an audio parallel stream from the external device to the bit stream processing unit.
146 Citations
4 Claims
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1. A low power audio processor comprising:
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a bit stream processing unit for bit processing an applied audio stream into a bit processed audio stream and for decoding the bit processed audio stream to have a format conducive to digital signal processing;
a digital signal processing unit for digital signal processing the decoded bit processed audio stream received from the bit stream processing unit to develop a digital signal processed audio stream;
a post processing unit for receiving the digital signal processed audio stream from the digital signal processing unit to develop final audio data;
a host interface unit for interfacing with an external device to provide an audio parallel stream received from the external device to the bit stream processing unit;
a power control unit for determining a power state for each of the bit stream processing unit, the digital signal processing unit and the post processing unit in response to;
(1) a request signal and an acknowledge signal between the digital signal processing unit and the post processing unit, (2) a power down signal, and (3) a source clock, the power control unit outputting a determined power state as a power mode signal; and
an internal clock signal generator unit for receiving the source clock and the power down signal and generating clock signals, each of the clock signals corresponding to a respective one of the bit stream processing unit, the digital signal processing unit and the post processing unit. - View Dependent Claims (2, 3, 4)
a first multiplexor for selectively outputting one of a DC level and the source clock in response to the power down signal;
a branch for branching the output of the first multiplexor into a predetermined number of branches; and
second, third and fourth multiplexors, each for selecting respective ones of the clock signals from the branch and the DC level in response to the power state of a corresponding one of the bit stream processing unit, the digital signal processing unit and to post processing unit outputting a selected signal to a respective one of the bit stream processing, digital signal processing and post processing units to output the selected signal to the corresponding processing unit.
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4. The audio processor as recited in claim 3, wherein the internal clock generator further includes a logic device for AND operating the outputs of the second, third and fourth multiplexors to drive a memory device.
Specification