Time-domain signal generation

• US 9,047,425 B2
• Filed: 11/18/2013
• Issued: 06/02/2015
• Est. Priority Date: 10/15/2005
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Hollis, Timothy M.
• Primary Examiner(s): PHAN, THAI Q
• Application Number:
  US14/083,062
• Publication Number:
  US 20140074446A1
• Time in Patent Office: 561 Days
• Field of Search: 703/2, 703/14, 703/17, 375/259
• US Class Current: 1/1
• CPC Class Codes: G06F 30/367 Design verification, e.g. using simulation, simulation program with integrated circuit emphasis [SPICE], direct methods or relaxation methods

Abstract

Methods and apparatus disclosed herein operate to receive a plurality of cycles characterized by a set of time-domain aspects, to modify at least one of the time-domain aspects of at least some of the plurality of cycles to produce a plurality of modified cycles, to process at least some of the modified cycles to produce time-domain cycles, and to create a time-domain signal based at least in part on concatenating the time-domain cycles.

Claims

1. A method, comprising:

generating an input waveform comprising a plurality of cycles, aspects of the input waveform being input and controllable by an end-user, the input waveform being representative of a communication stream in an electrical circuit;

calculating a set of transform coefficients for at least some of the plurality of cycles;

computing, using one or more hardware processors, a time-domain cycle for each set of transform coefficients; and

creating a time-domain signal based at least in part on concatenating the time-domain cycles.

2. The method of claim 1, further comprising providing at least one time-domain aspect of the input waveform for each of the plurality of cycles prior to calculating the set of transform coefficients.

3. The method of claim 1, further comprising calculating the set of transform coefficients as a function of the at least one time-domain aspect of the input waveform.

4. The method of claim 1, further comprising generating an aperiodic random data waveform comprising a plurality of cycles.

5. The method of claim 4, further comprising calculating the aperiodic random data waveform as a periodic waveform.

6. The method of claim 5, further comprising preparing a different NRZ symbol for each adjacent cycle within the plurality of cycles to generate the aperiodic random data waveform.

7. The method of claim 5, wherein the separate NRZ symbols includes at least four symbols to insure continuity at each cycle edge within the plurality of cycles, and piecing each of the plurality of cycles without discontinuity due to the NRZ signals.

8. The method of claim 4, preparing a separate non-return-to-zero (NRZ) symbol for each transition of a desired signal within the aperiodic random data waveform.

9. A method, comprising:

generating a plurality of cycles characterized by a set of time-domain aspects, the time-domain aspects being input and controllable by an end-user, the plurality of cycles being representative of a communication stream in an electrical circuit;

modifying at least one of the time-domain aspects of at least some of the plurality of cycles to produce a plurality of modified cycles;

processing at least some of the modified cycles to produce time-domain cycles; and

creating a time-domain signal based at least in part on concatenating the time-domain cycles.

10. The method of claim 9, wherein at least one of the time-domain aspects is selected from a group of aspects including a voltage level, a risetime, a falltime, a period, and a phase of a corresponding one of the plurality of cycles.

11. The method of claim 9, wherein the at least one of the time-domain aspects varies approximately randomly between the plurality of cycles.

12. The method of claim 9, wherein the at least one of the time-domain aspects varies deterministically between at least some of the plurality of cycles.

13. The method of claim 9, wherein the processing of the at least some of the modified cycles comprises a frequency transformation of each of the modified cycles followed by an inverse frequency transformation to produce each of the time-domain cycles.

14. The method of claim 13, wherein the frequency transformation is limited to a selected number of harmonics.

15. The method of claim 9, wherein each time-domain cycle comprises a constant time step.

16. The method of claim 15, wherein the time-domain aspects have a time resolution less than the time step.

17. A method, comprising:

generating a plurality of data symbols associated with a set of time-domain aspects of a data stream for communications between electrical devices, the time-domain aspects being input and controllable by an end-user;

modifying at least one of the time-domain aspects of at least some of the plurality of data symbols to produce a plurality of modified data symbols;

processing at least some of the modified data symbols to produce time-domain cycles; and

creating a time-domain signal based at least in part on concatenating the time-domain cycles.

18. The method of claim 17, wherein the set of time-domain aspects is associated with a communications stream comprised of random bits.

19. The method of claim 18, further comprising converting the communications stream of random bits into a plurality of data symbols.

20. The method of claim 19, wherein at least some of the plurality of data symbols have at least one time-domain aspect that varies randomly between the data symbols.

21. The method of claim 19, further comprising calculating a set of transform coefficients for each of the plurality of data symbols, each of the set of transform coefficients being calculated as a function of at least one time-domain aspect.

22. A method, comprising:

generating at least one time-domain aspect of a periodic input waveform, the at least one time-domain aspect being input and controllable by an end-user;

calculating transform coefficients using a finite number of harmonic frequencies, the transform coefficients being calculated as a function of the at least one time-domain aspect;

calculating effects on an electrical system communicating the input periodic input waveform including modifying the calculated transform coefficients with a previously determined transfer function of the electrical system to create output coefficients; and

processing at least one of the output coefficients to derive an output waveform.

23. The method of claim 22, further comprising modeling a source of noise in the electrical system including generating sinusoids as second input coefficients, frequencies of the sinusoids being different form harmonic frequencies of the transform coefficients.

24. The method of claim 23, further comprising:

calculating an additional effect on the electrical system including modifying the second input coefficients in accordance with the transfer function; and

generating a second set of output coefficients.

25. The method of claim 22, further comprising generating at least one varying time-domain aspect for each cycle of the periodic input waveform.

26. A tangible computer-readable medium having no transitory signals and containing instructions that, when executed by one or more hardware processors of a machine, cause the machine to perform operations comprising:

generating an input waveform comprising a plurality of cycles, the input waveform being representative of a communication stream in an electrical circuit;

calculating a set of transform coefficients for at least some of the plurality of cycles;

computing, using the one or more hardware processors, a time-domain cycle for each set of transform coefficients; and

creating a time-domain signal based at least in part on concatenating the time-domain cycles.

27. A tangible computer-readable medium having no transitory signals and containing instructions that, when executed by one or more hardware processors of a machine, cause the machine to perform operations comprising:

generating a plurality of cycles characterized by a set of time-domain aspects, the plurality of cycles being representative of a communication stream in an electrical circuit;

modifying at least one of the time-domain aspects of at least some of the plurality of cycles to produce a plurality of modified cycles;

processing at least some of the modified cycles to produce time-domain cycles; and

creating a time-domain signal based at least in part on concatenating the time-domain cycles.

28. A tangible computer-readable medium having no transitory signals and containing instructions that, when executed by one or more hardware processors of a machine, cause the machine to perform operations comprising:

generating a plurality of data symbols associated with a set of time-domain aspects of a data stream for communications between electrical devices;

modifying at least one of the time-domain aspects of at least some of the plurality of data symbols to produce a plurality of modified data symbols;

processing at least some of the modified data symbols to produce time-domain cycles; and

creating a time-domain signal based at least in part on concatenating the time-domain cycles.

29. A tangible computer-readable medium having no transitory signals and containing instructions that, when executed by one or more hardware processors of a machine, cause the machine to perform operations comprising:

generating at least one time-domain aspect of a periodic input waveform;

calculating transform coefficients using a finite number of harmonic frequencies, the transform coefficients being calculated as a function of the at least one time-domain aspect;

calculating the effect on an electrical system communicating the input periodic input waveform including modifying the calculated transform coefficients with a previously determined transfer function of the electrical system to create output coefficients; and

processing at least one of the output coefficients to derive an output waveform.