Oscillator array with row and column control

• US 20060220753A1
• Filed: 03/31/2005
• Published: 10/05/2006
• Est. Priority Date: 03/31/2005
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: Liberty, John Samuel, Hailu, Eskinder, Hofstee, Harm Peter, Boerstler, David William
• Granted Patent: US 7,233,212 B2
• Time in Patent Office: Days
• US Class Current: 331/46
• CPC Class Codes: G06F 7/588 Random number generators, i.e. based on natural stochastic processes
• CPC Class Codes: H03K 3/0315 Ring oscillators
• CPC Class Codes: H03K 3/84 Generating pulses having a predetermined statistical distribution of a parameter, e.g. random pulse generators

Abstract

A circuit topology which can be used to create an array of individually tuned oscillators operating at different frequencies determined by common control inputs and an easily managed variation in design dimensions of several components is provided. An array of oscillators are provided arranged in columns and rows. Each oscillator in a column is unique from the other oscillators in the column based on number of stages in the oscillator and fanout so that each oscillator will operate at a unique frequency. Oscillators of different columns within the array may differ by a common setting of the selects to these oscillators and the physical ordering of the oscillators in the column to further reduce the possibility of injection locking. A base delay cell provides selects to each column of oscillators such that each column may be programmed to operate at a different frequency from its neighbors.

Claims

1. An oscillator array, comprising:

a plurality of oscillator columns, wherein each oscillator column has a plurality of oscillators; and

a plurality of input lines coupled to the plurality of oscillators in the plurality of oscillator columns, wherein each oscillator in the oscillator array generates a frequency output, based on input signals provided via the plurality of input lines, that is unique from every other oscillator in the oscillator array, and wherein the frequency output is not harmonically related to any other frequency output of any other oscillator in the oscillator array.

2. The oscillator array of claim 1, wherein the frequency output that is generated by each oscillator is based on a number of stages of the oscillator, a delay associated with each stage of the oscillator, a fanout of the oscillator, and a setting of input signals input to the oscillator.

3. The oscillator array of claim 1, wherein each oscillator in the oscillator array includes one or more delay elements, and wherein the one or more delay elements cause the oscillator to generate a different frequency output based on a setting of input signals input to the one or more delay elements.

4. The oscillator array of claim 1, wherein one or more outputs of the oscillator array are coupled to a cryptographic element which uses the one or more outputs of the oscillator array to perform cryptographic operations.

5. The oscillator array of claim 4, wherein the cryptographic element is a random number generator element.

6. The oscillator array of claim 1, wherein each oscillator in a same oscillator column is unique from the other oscillators in the same oscillator column based on a combination of a number of stages in the oscillator and a fanout of the oscillator.

7. The oscillator array of claim 1, wherein oscillators of different columns within the oscillator array differ from one another at least by a setting of the input signals to these oscillators and a physical ordering of the oscillators in their respective oscillator columns.

8. The oscillator array of claim 1, wherein the oscillator array includes 8 oscillator columns and each oscillator column includes 8 oscillators, and wherein an output of the oscillator array is a 64 bit value.

9. The oscillator array of claim 1, wherein every oscillator column in the oscillator array has an opposite arrangement of oscillators from its neighboring oscillator column or columns.

10. The oscillator array of claim 3, wherein each of the delay elements includes a plurality of stages, and wherein each stage includes an inverter and a pass gate, and wherein the inverters of each stage have a different strength than inverters of other stages in the delay element.

11. A method of making an oscillator array, comprising:

providing a plurality of oscillator columns, wherein each oscillator column has a plurality of oscillators; and

providing a plurality of input lines coupled to the plurality of oscillators in the plurality of oscillator columns, wherein each oscillator in the oscillator array generates a frequency output, based on input signals provided via the plurality of input lines, that is unique from every other oscillator in the oscillator array, and wherein the frequency output is not harmonically related to any other frequency output of any other oscillator in the oscillator array.

12. The method of claim 11, wherein the frequency output that is generated by each oscillator is based on a number of stages of the oscillator, a delay associated with each stage of the oscillator, a fanout of the oscillator, and a setting of input signals input to the oscillator.

13. The method of claim 11, wherein each oscillator in the oscillator array includes one or more delay elements, and wherein the one or more delay elements cause the oscillator to generate a different frequency output based on a setting of input signals input to the one or more delay elements.

14. The method of claim 11, further comprising:

providing a cryptographic element coupled to the oscillator array, wherein one or more outputs of the oscillator array are coupled to the cryptographic element which uses the one or more outputs of the oscillator array to perform cryptographic operations.

15. The method of claim 14, wherein the cryptographic element is a random number generator element.

16. The method of claim 11, wherein each oscillator in a same oscillator column is unique from the other oscillators in the same oscillator column based on a combination of a number of stages in the oscillator and a fanout of the oscillator.

17. The method of claim 11, wherein oscillators of different columns within the oscillator array differ from one another at least by a setting of the input signals to these oscillators and a physical ordering of the oscillators in their respective oscillator columns.

18. The method of claim 11, wherein every oscillator column in the oscillator array has an opposite arrangement of oscillators from its neighboring oscillator column or columns.

19. The method of claim 13, wherein each of the delay elements includes a plurality of stages, and wherein each stage includes an inverter and a pass gate, and wherein the inverters of each stage have a different strength than inverters of other stages in the delay element.

20. A data processing device, comprising:

control logic; and

an oscillator array coupled to the control logic, wherein the oscillator array includes a plurality of oscillator columns and each oscillator column has a plurality of oscillators, and wherein;

the control logic provides a plurality of input signals to the plurality of oscillators in the plurality of oscillator columns;

each oscillator in the oscillator array generates a frequency output, based on the input signals provided by the control logic, that is unique from every other oscillator in the oscillator array; and

the frequency output by each oscillator in the oscillator array is not harmonically related to any other frequency output of any other oscillator in the oscillator array.