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US 10,770,146 B2Granted
Method and apparatus for PUF generator characterization
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorShih-Lien Linus Lu
Life of this patent
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Abstract
Disclosed is a physical unclonable function generator circuit and testing method. In one embodiment, a testing method for physical unclonable function (PUF) generator includes: verifying a functionality of a PUF generator by writing preconfigured logical states to and reading output logical states from a plurality of bit cells in a PUF cell array; and determining whether the PUF generator is a qualified PUF generator based on whether one or more predefine quality criteria is satisfied.
Claims20
A method for testing a physical unclonable function (PUF) generator, the method comprising:
- verifying a functionality of a PUF generator by writing preconfigured logical states to and reading output logical states from a plurality of bit cells in a PUF cell array;
- determining a first number of first bit cells in the PUF cell array, wherein the output logical states of the first bit cells are different from the preconfigured logical states;
- if the first number of first bit cells is less than a first predetermined number, generating a first map under a first set of operation conditions using the PUF generator and a masking circuit, wherein the first map comprises at least one stable bit cells and at least one unstable bit cell, wherein the first set of operation conditions comprises a first operating temperature and a first operating voltage applied to the PUF cell array;
- generating a second map under a second set of operation conditions using the PUF generator and the masking circuit, wherein the second map comprises at least one stable bit cells and at least one unstable bit cell, wherein the second set of operation conditions comprises a second operating temperature and a second operating voltage applied to the PUF cell array;
- determining a second number of second bit cells, wherein the second bit cells are stable in the first map and unstable in the second map using a Built-in Self Test (BIST) engine;
- if the second number of second bit cells is determined to be zero, determining a third number of third bit cells using the BIST engine, wherein the third bit cells are stable in the first map and stable in the second map;
- and
- if the third number of third bit cells are greater than a second preconfigured number, the PUF generator is determined as a qualified PUF generator that meets a predefined quality criterion.
5 more elements
A physical unclonable function (PUF) generator comprising:
- a PUF cell array comprising a plurality of bit cells, wherein the plurality of bit cells each provides a logical state;
- a controller coupled to the PUF cell array, wherein the controller is configured to provide a first set and a second set of operation conditions to the PUF cell array, wherein the first set of operation conditions comprises a first operating temperature and a first operating voltage applied to the PUF cell array and the second set of operation conditions comprises a second operating temperature and a second operating voltage applied to the PUF cell array;
- a masking circuit configured to determine a first map and a second map, wherein the first and second maps determined under the first and second set of operation conditions, respectively, each comprises a plurality of logical states of the plurality of bit cells in the PUF cell array, wherein the first and second maps each comprises at least one stable bit cells and at least one unstable bit cell;
- and
- a Built-In Self Test (BIST) engine, configured to determine a first number of first bit cells and a second number of second bit cells, wherein the first bit cells are stable in the first map and unstable in the second map, wherein the second bit cells are stable in the first map and stable in the second map, wherein if the second number of second bit cells is greater than a predetermined threshold, the PUF generator is determined as a qualified PUF generator that meets a predefined quality criterion based at least on the second number being greater than the predetermined threshold.
2 more elements
A physical unclonable function (PUF) generator comprising:
- a PUF cell array comprising a plurality of bit cells, wherein the plurality of bit cells each comprises two cross-coupled inverters;
- at least two access transistors, at least one enable transistor, and at least two storage nodes, wherein the at least two storage nodes are pre-configured with the same voltages allowing each of the plurality of bit cells having a first metastable logical state;
- a controller coupled to the PUF cell array, wherein the controller comprising a delay circuit is configured to provide a first set and a second set of operation conditions to the PUF cell array, wherein the first set of operation conditions comprises a first operating temperature and a first operating voltage applied to the PUF cell array and the second set of operation conditions comprises a second operating temperature and a second operating voltage applied to the PUF cell array;
- a masking circuit configured to determine a first map and a second map, wherein the first and second maps determined under the first and second set of operation conditions, respectively, each comprises a plurality of logical states of the plurality of bit cells in the PUF cell array, wherein the first and second maps each comprises at least one stable bit cells and at least one unstable bit cell;
- and
- a Built-In Self Test (BIST) engine, configured to determine a first number of first bit cells and a second number of second bit cells, wherein the first bit cells are stable in the first map and unstable in the second map, wherein the second bit cells are stable in the first map and stable in the second map, wherein if the second number of second bit cells is greater than a predetermined threshold, the PUF generator is determined as a qualified PUF generator that meets a predefined quality criterion based at least on the second number being greater than the predetermined threshold.
3 more elements
Dependencies are inferred from the claim text.