Programmable circuit with preview function
AssigneeXerox Corporation
InventorChristopher R. Morton
Life of this patent
Estimating the term…
Abstract
A programmable circuit and method of programming that provide an easily fabricated circuit that does not require specialize manufacturing or packaging techniques. The circuit provides for temporarily setting the circuit outputs which can then be used for testing. The circuit also provides for permanently setting the output by applying sufficient voltage and current to the transistor that permanent spiking of the metallized contact layer through the junction occurs.
Claims14
A programmable circuit, connected to a first voltage source providing a predetermined voltage comprising:
- a first input structure connected to a common node, wherein when a first signal is placed on the first input structure, the output state of the programmable circuit is temporarily set;
- a transistor connected to a second voltage source providing a second predetermined voltage and to the common node;
- a resistor connected between the first voltage source and the common node;
- a second input structure connected to the transistor;
- wherein, when a programming enable signal is applied to the second input structure, a programming signal applied to the first input structure permanently sets the output state of the programmable circuit;
- and
- wherein the transistor uses a gallium arsenide manufacturing technique.
A programmable circuit, connected to a first voltage source providing a predetermined voltage comprising:
- a first input structure connected to a common node, wherein when a first signal is placed on the first input structure, the output state of the programmable circuit is temporarily set;
- a transistor connected to a second voltage source providing a second predetermined voltage and to the common node;
- a resistor connected between the first voltage source and the common node;
- a second input structure connected to the transistor;
- wherein, when a programming enable signal is applied to the second input structure, a programming signal applied to the first input structure permanently sets the output state of the programmable circuit;
- and
- wherein the programming signal is sufficient to cause the metallization layers of the transistor to spike into a substrate of the transistor.
A method of non-permanently programming and reading a programmable previewable circuit comprising:
- a first input structure connected to a common node;
- a transistor connected to the common node;
- a resistor connected between a first voltage source and the common node;
- a second input structure connected to the transistor;
- wherein non-permanently setting the programmable previewable circuit comprises the steps of:
- applying a non-enabling signal to the second input structure;
- applying a desired signal to the first input structure;
- reading an output signal from the common node structure which is a function of the desired signal;
- and
- wherein the transistor uses a gallium arsenide manufacturing technique.
A method of non-permanently programming and reading a programmable previewable circuit comprising:
- a first input structure connected to a common node;
- a transistor connected to the common node;
- a resistor connected between a first voltage source and the common node;
- a second input structure connected to the transistor;
- wherein non-permanently setting the programmable previewable circuit comprises the steps of:
- applying a non-enabling signal to the second input structure;
- applying a desired signal to the first input structure;
- reading an output signal from the common node structure which is a function of the desired signal;
- and
- wherein applying the programming signal is sufficient to cause the metallization layers of the transistor to spike into a substrate of the transistor.
In an electronic circuit, a method of setting a selectable impedance element that is connected between a node and a first source, the method comprising:
- setting the selectable impedance to a first state;
- applying a first input to the node of the electronic circuit;
- setting the selectable impedance to a second state;
- applying a second input to the node while the selectable impedance is in the second state, wherein the second input alters the selectable impedance.
Dependencies are inferred from the claim text.