Dual signal protocol input/output (I/O) buffer circuit
First Claim
1. An integrated circuit device, comprising:
- a first input/output (I/O) buffer circuit transferring signals based on a given signal transmission protocol selected from a group of signal transmission protocols, wherein the first input/output buffer circuit comprises;
first and second groups of stacked transistors, wherein the first group of stacked transistors transfers signals formatted in accordance with a first signal transmission protocol from the group of signal transmission protocols, and the second group of stacked transistors transfers the signals formatted in accordance to a plurality of signal transmission protocols from the group of signal transmission protocols, wherein the first input/output buffer circuit transfers the signals formatted in accordance with the first signal transmission protocol by activating both the first and second groups of stacked transistors, and wherein the first input/output buffer circuit transfers the signals formatted in accordance with the second signal transmission protocol by activating only one of the first and second groups of stacked transistors and biasing a subset of the transistors in the selectively activated one of the first and second groups of stacked transistors at an intermediate voltage that is different from voltages applied to activate or deactivate transistors, wherein the group of signal transmission protocols includes a single ended signal transmission protocol and a differential signal transmission protocol.
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Accused Products
Abstract
An integrated circuit (IC) device includes a first input/output (I/O) buffer circuit. The first input/output buffer circuit includes first and second groups of stacked transistors. The first group of stacked transistors transfer signals formatted in accordance with only one signal protocol from the group of signal protocols. The second group of stacked transistors transfers the signals formatted in accordance with more than one signal protocols. In addition, integrated circuit device also includes a second input/output buffer circuit. The second input/output buffer circuit includes third and fourth groups of stacked transistors. The third group of stacked transistors transfers the signals formatted in accordance to the first signal transmission protocol from the group of signal transmission protocols. The fourth group of stacked transistors transfers the signals formatted in accordance to the plurality of signal transmission protocols from the group of signal transmission protocols.
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Citations
19 Claims
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1. An integrated circuit device, comprising:
a first input/output (I/O) buffer circuit transferring signals based on a given signal transmission protocol selected from a group of signal transmission protocols, wherein the first input/output buffer circuit comprises; first and second groups of stacked transistors, wherein the first group of stacked transistors transfers signals formatted in accordance with a first signal transmission protocol from the group of signal transmission protocols, and the second group of stacked transistors transfers the signals formatted in accordance to a plurality of signal transmission protocols from the group of signal transmission protocols, wherein the first input/output buffer circuit transfers the signals formatted in accordance with the first signal transmission protocol by activating both the first and second groups of stacked transistors, and wherein the first input/output buffer circuit transfers the signals formatted in accordance with the second signal transmission protocol by activating only one of the first and second groups of stacked transistors and biasing a subset of the transistors in the selectively activated one of the first and second groups of stacked transistors at an intermediate voltage that is different from voltages applied to activate or deactivate transistors, wherein the group of signal transmission protocols includes a single ended signal transmission protocol and a differential signal transmission protocol. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An integrated circuit device, comprising:
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a first input/output (I/O) buffer circuit that transfers signals in accordance to a given signal transmission protocol selected from first and second signal transmission protocols; and a second input/output (I/O) buffer circuit that transfer signals in accordance to the given signal transmission protocol, wherein a first subset of transistors in the second I/O buffer circuit is deactivated by biasing the first subset of transistors with a first voltage when the second I/O buffer circuit transfers signals in accordance to the given signal transmission protocol, wherein a second subset of transistors in the second I/O buffer circuit is activated by biasing the second subset of transistors with a second voltage when the second I/O buffer circuit transfers signals in accordance to the given signal transmission protocol, and wherein a third subset of transistors in the second I/O buffer circuit is biased at an intermediate voltage that is between the first and second voltages; and interconnections coupled to the first and second I/O buffer circuits, wherein the signal interconnections are disabled when the first and second I/O buffer circuits are configured to receive signals according to either the first or second signal transmission protocols. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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14. A method of operating an integrated circuit device that comprises first, second, third and fourth groups of stacked transistors, wherein the method comprises:
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receiving configuration information for the first, second, third and fourth groups of stacked transistors; and configuring the first, second, third and fourth stacked transistors using the received configuration information to transfer signals in accordance to a selected signal transmission protocol from a group of first and second signal transmission protocols, wherein transmitting signals according to the first signal transmission protocol comprises activating the first, second, third, and fourth groups of stacked transistors, and wherein transmitting signals according to the second signal transmission protocol comprises activating only the first and third groups of stacked transistors by biasing a first transistor in the first group of stacked transistors at a first voltage, biasing a second transistor in the first group of stacked transistors at an second voltage that is less than the first voltage, and biasing a third transistor in the second group of stacked transistors at a third voltage, wherein the first signal transmission protocol is a double data rate signal transmission protocol and the second signal transmission protocol is a low voltage differential single (LVDS) protocol. - View Dependent Claims (15, 16, 17, 18, 19)
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Specification