Circuits and methods for reducing pin count in multiple-mode integrated circuit devices
AssigneeCirrus Logic, Inc.
InventorBruce Eliot Duewer
Life of this patent
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Abstract
A method of controlling a terminal of an integrated circuit includes determining a frequency ratio between a frequency of a signal and a frequency of another signal received by an integrated circuit. A selected signal appearing at a selected terminal of the integrated circuit is selectively interpreted in accordance with an operating mode when the frequency ratio is below a selected value and in accordance with another operating mode when the frequency of the signal is above a selected value.
Claims16
A method of controlling a terminal of an integrated circuit to reduce terminal count of an integrated circuit:
- comprising:
- receiving at corresponding terminals of an integrated circuit a signal and another signal from a source device;
- determining a frequency ratio between a frequency of the signal and a frequency of the other signal received by the integrated circuit;
- selectively interpreting a selected signal appearing at a selected multiple-purpose input terminal of the integrated circuit in accordance with an operating mode when the frequency ratio is below a selected value and in accordance with another operating mode when the frequency ratio is above a selected value;
- and
- operating on the selected signal in response to the corresponding one of the operating mode and another operating mode to generate an output signal for controlling a destination device, and thereby allow the terminal count of the integrated circuit to be reduced.
An integrated circuit comprising:
- ratio detection circuitry for determining a ratio between a frequency of a signal and a frequency of another signal received by an integrated circuit;
- and
- at least one multiple-purpose input terminal for receiving a selected signal in a first operating mode when the ratio is below a selected value and another selected signal in a second operating mode when the ratio is above the selected value, the multiple-purpose input terminal reducing a terminal count on the integrated circuit.
Dependencies are inferred from the claim text.