Device, system, and method to change a consistency of behavior by a cell circuit

Patent metadata

Field	Value
Publication number	US-10825511-B2
Application number	US-201916417538-A
Country	US
Kind code	B2
Filing date	May 20, 2019
Priority date	Mar 29, 2019
Publication date	Nov 3, 2020
Grant date	Nov 3, 2020

Abstract

Techniques and mechanisms for changing a consistency with which a cell circuit (“cell”) settles into a given state. In one embodiment, a cell settles into a preferred state based on a relative polarity between respective voltages of a first rail and a second rail. Based on the preferred state, a hot carrier injection (HCI) stress is applied to change a likelihood of the cell settling into the preferred state. Applying the HCI stress includes driving off-currents of two PMOS transistors of the cell while the relative polarity is reversed. In another embodiment, a cell array comprises multiple cells which are each classified as being a respective one of a physically unclonable function (PUF) type or a random number generator (RNG) type. A cell is selected for biasing, and a stress is applied, based on each of: that cell's preferred state, that cell's classification, and another cell's classification.

First claim

What is claimed is:

1. A device for biasing a circuit, the device comprising:
first circuitry to identify a first cell circuit of a cell array as being of a first cell type which is one of a physically unclonable function (PUF) cell type or a random number generator (RNG) cell type, the first circuitry further to identify a second cell circuit of the cell array as being of a second cell type which is one of the PUF cell type or the RNG cell type;
second circuitry to determine a preferred state of the first cell circuit, wherein, during the preferred state, two nodes of the first cell circuit each provide a different respective one of first complementary signals;
third circuitry to identify a stress scheme based on each of the preferred state, the first cell type and the second cell type; and
fourth circuitry to stress the first cell circuit according to the stress scheme, including the fourth circuitry to provide second complementary signals each at a different respective node of the two nodes.

2. The device of claim 1 , wherein, based on the stress, the first cell circuit is to more strongly exhibit a characteristic of the RNG cell type.

3. The device of claim 1 , wherein the third circuitry is to identify the stress scheme further based on a threshold number of cells in a column or row of the cell array which are of the RNG cell type, wherein the column or row comprises the first cell circuit.

4. The device of claim 1 , wherein the third circuitry is to identify the stress scheme further based on a threshold ratio of a number of cell circuits which are of the PUF cell type to a number of cell circuits which are of the RNG cell type.

5. The device of claim 1 , wherein, based on the stress, the first cell circuit is to more strongly exhibit a characteristic of the PUF cell type.

6. The device of claim 1 , wherein, based on the stress, the first cell circuit transitions between being the PUF cell type and being of the RNG cell type.

7. The device of claim 1 , further comprising:
fifth circuitry to evaluate, for each cell circuit of multiple cell circuits of the cell array, a respective likelihood that the cell circuit will settle to a first state; and
sixth circuitry, responsive to the fifth circuitry, to select the first cell circuit from among the multiple cell circuits, wherein the fourth circuitry is to stress the first cell circuit responsive to the sixth circuitry.

8. The device of claim 7 , wherein the sixth circuitry to select the first cell circuit from among the multiple cell circuits comprises the sixth circuitry to determine that, of the multiple cell circuits, the first cell circuit is most easily transitioned between being of the PUF cell type and being of the RNG cell type.

9. One or more computer-readable storage media having stored thereon instructions which, when executed by one or more processing units, cause the one or more processing units to perform a method comprising:
identifying a first cell circuit of a cell array as being of a first cell type which is one of a physically unclonable function (PUF) cell type or a random number generator (RNG) cell type;
identifying a second cell circuit of the cell array as being of a second cell type which is one of the PUF cell type or the RNG cell type;
determining a preferred state of the first cell circuit, wherein, during the preferred state, two nodes of the first cell circuit each provide a different respective one of first complementary signals;
identifying a stress scheme based on each of the preferred state, the first cell type and the second cell type; and
stressing the first cell circuit according to the stress scheme, including providing second complementary signals each at a different respective node of the two nodes.

10. The one or more computer-readable storage media of claim 9 , wherein, based on the stress, the first cell circuit more strongly exhibits a characteristic of the RNG cell type.

11. The one or more computer-readable storage media of claim 9 , wherein identifying the stress scheme is further based on a threshold number of cells in a column or row of the cell array which are of the RNG cell type, wherein the column or row comprises the first cell circuit.

12. The one or more computer-readable storage media of claim 9 , wherein identifying the stress scheme is further based on a threshold ratio of a number of cell circuits which are of the PUF cell type to a number of cell circuits which are of the RNG cell type.

13. The one or more computer-readable storage media of claim 9 , wherein, based on the stress, the first cell circuit transitions between being the PUF cell type and being of the RNG cell type.

14. The one or more computer-readable storage media of claim 9 , further comprising:
evaluating, for each cell circuit of multiple cell circuits of the cell array, a respective likelihood that the cell circuit will settle to a first state;
based on the evaluating, selecting the first cell circuit from among the multiple cell circuits, wherein the stress is based on the selecting.

15. A system comprising:
an integrated circuit (IC) comprising:
first circuitry to identify a first cell circuit of a cell array as being of a first cell type which is one of a physically unclonable function (PUF) cell type or a random number generator (RNG) cell type, the first circuitry further to identify a second cell circuit of the cell array as being of a second cell type which is one of the PUF cell type or the RNG cell type;
second circuitry to determine a preferred state of the first cell circuit, wherein, during the preferred state, two nodes of the first cell circuit each provide a different respective one of first complementary signals;
third circuitry to identify a stress scheme based on each of the preferred state, the first cell type and the second cell type; and
fourth circuitry to stress the first cell circuit according to the stress scheme, including the fourth circuitry to provide second complementary signals each at a different respective node of the two nodes; and

a display device coupled to the IC, the display device to display an image based on a signal communicated with the cell circuit.

16. The system of claim 15 , wherein the third circuitry is to identify the stress scheme further based on a threshold number of cells in a column or row of the cell array which are of the RNG cell type, wherein the column or row comprises the first cell circuit.

17. The system of claim 15 , wherein the third circuitry is to identify the stress scheme further based on a threshold ratio of a number of cell circuits which are of the PUF cell type to a number of cell circuits which are of the RNG cell type.

18. The system of claim 15 , wherein, based on the stress, the first cell circuit transitions between being the PUF cell type and being of the RNG cell type.

19. The system of claim 15 , further comprising:
fifth circuitry to evaluate, for each cell circuit of multiple cell circuits of the cell array, a respective likelihood that the cell circuit will settle to a first state; and
sixth circuitry, responsive to the fifth circuitry, to select the first cell circuit from among the multiple cell circuits, wherein the fourth circuitry is to stress the first cell circuit responsive to the sixth circuitry.

20. The system of claim 19 , wherein the sixth circuitry to select the first cell circuit from among the multiple cell circuits comprises the sixth circuitry to determine that, of the multiple cell circuits, the first cell circuit is mo

Assignees

• Intel Corp

Inventors

• De Vivek
• Mathew Sanu
• Satpathy Sudhir
• Suresh Vikram
• Kumar Raghavan

Classifications

• G09C1/00

  Apparatus or methods whereby a given sequence of signs, e.g. an intelligible text, is transformed into an unintelligible sequence of signs by transposing the signs or groups of signs or by replacing them by others according to a predetermined system (cryptographic typewriters G09C3/00) · CPC title

• H10D64/511

  for IGFETs · CPC title

• H10D30/685

  from the channel · CPC title

• H04L9/3278

  using physically unclonable functions [PUF] · CPC title

• H04L9/0866

  involving user or device identifiers, e.g. serial number, physical or biometrical information, DNA, hand-signature or measurable physical characteristics · CPC title