Increment/decrement sampling phase shifter
AssigneeTexas Instruments Incorporated
InventorsRichard K. Hester, Nuboru Shiwaku
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Abstract
An analog interface system interfaces with a digital signal processor. The system receives analog signals, digitizes those signals and transmits them to the signal processor upon completion of the conversion. The system directs transmission of digital data from the signal processor to the system, and converts it to analog as the output of the system. The digital signal processor determines whether the sampling rate of the D-to-A and A-to-D converters is correct for the rate at which the data is being received by the respective converters. If not, the DSP sends a number of master clock cycles to the system which then retards or advances the sampling rate of the converter by that number of clock cycles.
Claims5
An analog interface system for interfacing with a digital signal processor having an analog-to-digital converter of digitally selectable sample rate and a digital-to-analog converter of digitally selectable sample rate for converting input analog data signals and output digital data signals, respectively, a communication bus and means for detecting a sampling rate mismatch between said converters and the amplitude of said mismatch, for transmitting the mismatch amplitude on the communication bus to the analog interface system, comprising:
- (a) an analog input channel including the analog-to-digital converter, input means for receiving the input analog data signals and transmitting the input analog data signals to the analog-to-digital converter for conversion to input digital data signals, and output means connected to the communication bus for transmitting of the input digital signals to the digital signal processor;
- (b) an analog output channel including the digital-to-analog converter, input means connected to the communication bus for receiving the output digital data signals from the digital signal processor and transmitting the output digital data signals to the digital-to-analog converter for conversion into analog output signals;
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- (c) increment/decrement means connected to receive the input analog signals from the input means to indicate the amplitude of mismatch and the required direction of change of sampling rate for advancing or retarding the sampling rate of said converters in accordance with the amplitude of the mismatch.
Dependencies are inferred from the claim text.