Merged programmable output driver
AssigneeMeta Systems
InventorJean Barbier
Life of this patent
Estimating the term…
Abstract
Embodiments provide input/output devices having programmable logic that is programmable to operate input/output devices in one of two drive modes. In various embodiments, to operate an input/output device in a first drive mode, logic circuitry is programmable to couple a reference voltage to a gate of a transistor element of an output driver. In various embodiments, to operate an input/output device in a second drive mode, the logic circuitry is programmable to couple a bias voltage to the gate of the transistor element of the output driver. In various embodiments, the logic circuitry may also be programmable to couple one of a plurality of data inputs to the output driver to operate an input/output device in either a single-ended mode or a differential mode.
Claims19
An apparatus;
- comprising:
- an output driver comprising:
- an output node,
- a first PMOS transistor having a source node coupled to a supply voltage,
- a second PMOS transistor having a source node coupled to a drain node of the first PMOS transistor and a drain node coupled to the output node, and
- a third PMOS transistor having a source node coupled to the supply voltage and a drain node coupled to the output node, and
- logic circuitry coupled to the output driver, the logic circuitry including one or more circuit elements arranged to enable the logic circuitry to be programmable to apply either:
- a predetermined reference voltage to a gate of the first PMOS transistor to operate the apparatus in a voltage-drive mode, or
- a bias voltage to the gate of the first PMOS transistor to operate the apparatus in a current-drive mode, wherein:
- the output driver is a first output driver;
- the apparatus further comprises a second output driver comprising a fourth PMOS transistor having a source node coupled to the supply voltage;
- the logic circuitry is coupled to the second output driver;
- the logic circuitry is further programmable to selectively apply the predetermined reference voltage to a gate of the fourth PMOS transistor to operate the apparatus in the voltage-drive mode;
- and
- the logic circuit is further programmable to selectively apply the bias voltage to the gate of the fourth PMOS transistor to operate the apparatus in the current-drive mode.
A method, comprising:
- receiving, by a logic circuitry of an input/output device, an instruction to operate the input/output device in a drive mode, wherein the input/output device includes an output driver having a first PMOS transistor coupled to a supply voltage and second and third PMOS transistors coupled to an output node;
- coupling, by the logic circuitry in response to receiving the instruction, a voltage to a gate of the first PMOS transistor to operate the integrated circuit in the drive mode, wherein the voltage is a selected one of a reference voltage, or a bias voltage;
- receiving, by the logic circuitry, another instruction to operate the input/output device in either a single-ended drive mode or a differential drive mode;
- and
- selectively coupling one of two data inputs to the output driver, based at least on the other instruction.
Dependencies are inferred from the claim text.