Multi-Modal Communication Interface
AssigneeRambus Inc.
InventorsAmir Amirkhany, Chaofeng Huang
Life of this patent
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Abstract
An integrated circuit supports multiple communication modes using different input/output (IO) voltages. The IC includes a low-voltage communication circuit operating at a low IO voltage in a low-voltage mode, and a high-voltage communication circuit operating at a high IO voltage in a high-voltage mode. The low-voltage communication circuit includes low-voltage transistors in a critical path that exhibits sensitivity to a destructive voltage less than the high IO voltage. The low-voltage communication circuit is therefore provided with protection circuitry to protect the low-voltage transistors from the high 10 voltage.
Claims25
An integrated circuit comprising:
- an input/output (IO) supply node to supply a low IO voltage in a low-voltage mode or a high IO voltage in a high-voltage mode;
- a data input port and a data output port;
- and
- alternative low-voltage and high-voltage communication circuits connected between the data input port and the data output port, and to the IO supply node, the low-voltage and high-voltage communication circuits to convey data signals between the data input port and the data output port in the respective low-voltage and high-voltage modes;
- the low-voltage communication circuit further including:
- low-voltage transistors defining a critical path for the data signals in the low-voltage mode, each of the low-voltage transistors having first and second current-handling terminals and a control terminal and exhibiting a sensitivity to a destructive voltage less than the high IO voltage between any two of the first and second current-handling terminals and the control terminal;
- wherein the low-voltage communication circuit is inactive in the high-voltage mode and the first and second current-handling terminals and the control terminals are set to protection voltage levels in the high-voltage mode.
A driver supporting first and second communication modes, the driver comprising:
- a first supply node to supply a first core supply voltage;
- a second supply node to supply a second core supply voltage;
- a third supply node to alternatively supply first or second input/output (IO) voltages relative to the first core supply voltage, the first IO voltage being supplied in the first communication mode and the second IO voltage, greater than the first IO voltage, being supplied in the second communication mode;
- a driver amplifier extending between the first and third supply nodes and having first and second driver input nodes and a driver output node;
- and
- a first predriver coupled between the first supply node and each of the second and third supply nodes, the first predriver including a first predriver output node coupled to the first driver input node, wherein the first predriver output node transitions between the first core supply voltage and the first IO voltage in the first communication mode and remains at the second IO voltage in the second communication mode.
A computer-readable medium having stored thereon a data structure defining a driver adapted to transmit output signals in first and second communication modes, the data structure comprising:
- first data representing a first supply node to supply a first core supply voltage;
- second data representing a second supply node to supply a second core supply voltage;
- third data representing a third supply node to alternatively supply, relative to the first core supply voltage, a first input/output (IO) voltage in the first communication mode or a second IO voltage, greater than the first IO voltage, in the second communication mode;
- fourth data representing a driver amplifier extending between the first and third supply node and having first and second driver input nodes and a driver output node;
- and
- fifth data representing a predriver coupled between the first supply node and each of the second and third supply nodes, the predriver including a predriver input node and a predriver output node coupled to the first driver input node, wherein the predriver output node transitions between the first core supply voltage and the first IO voltage in the first communication mode and remains at the second IO voltage in the second communication mode.
A method for supporting a high-voltage (HV) signaling scheme and a low-voltage (LV) signaling scheme for communicating a signal using alternative HV and LV communication circuits, the method comprising:
- in an HV mode supporting the HV signaling scheme,
- providing an HV IO voltage to the HV communication circuit,
- providing an HV IO voltage to a critical path in the LV communication circuit,
- setting terminals of low-voltage transistors in the critical path to protection voltage levels, and
- in an LV mode supporting the LV signaling scheme,
- providing an LV IO voltage to the LV communication circuit, and
- communicating the signal via the critical path of the LV communication circuit.
Dependencies are inferred from the claim text.