INTEGRATED CIRCUIT HAVING A CLOCK DESKEW CIRCUIT THAT INCLUDES AN INJECTION-LOCKED OSCILLATOR

• US 20160226504A1
• Filed: 01/07/2016
• Published: 08/04/2016
• Est. Priority Date: 03/03/2011
• Status: Active Grant

• Current Assignee: Rambus Inc.
• Original Assignee: Rambus Inc.
• Inventors: Aleksic, Marko, Leibowitz, Brian S.
• Granted Patent: US 9,564,912 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H03K 2005/00286 Phase shifter, i.e. the delay between the output and input pulse is dependent on the frequency, and such that a phase difference is obtained independent of the frequency
• CPC Class Codes: H03K 5/26 the characteristic being duration, interval, position, frequency, or sequence
• CPC Class Codes: H03L 7/081 provided with an additional controlled phase shifter H03L7/0998 takes precedence
• CPC Class Codes: H03L 7/099 concerning mainly the controlled oscillator of the loop
• CPC Class Codes: H03L 7/0995 the oscillator comprising a ring oscillator
• CPC Class Codes: H03L 7/24 using a reference signal directly applied to the generator

Abstract

Methods and apparatuses featuring an injection-locked oscillator (ILO) are described. In some embodiments, an ILO can have multiple injection points and a free-running frequency that is capable of being adjusted based on a control signal. In some embodiments, each injection point of an ILO can correspond to a phase tuning range. In some embodiments, a circuit can include circuitry to detect a phase boundary between two adjacent phase tuning ranges. In some embodiments, a circuit can use the detected phase boundary to switch between the two adjacent phase tuning ranges.

Claims

1. A circuit, comprising:

an injection-locked oscillator (ILO) having a free-running frequency that is controlled by at least a control value; and

circuitry to determine at least a first control value that corresponds to a phase boundary between two adjacent phase tuning ranges of the ILO.

2. The circuit of claim 1, further comprising circuitry to store the first control value.

3. The circuit of claim 2, further comprising circuitry to determine a second control value that corresponds to a phase difference with respect to a reference phase, wherein the second control value is determined based on the stored first control value.

4. The circuit of claim 3, further comprising circuitry to provide the second control value to the ILO.

5. The circuit of claim 1, wherein the circuitry to determine at least the first control value comprises circuitry to select an injection point of the ILO, wherein the injection point corresponds to one of the two adjacent phase tuning ranges of the ILO.

6. The circuit of claim 5, wherein the circuitry to determine at least the first control value comprises circuitry to sweep the free-running frequency of the ILO until the phase boundary between the two adjacent phase tuning ranges of the ILO is detected.

7. The circuit of claim 1, wherein the ILO is based on a ring oscillator.

8. The circuit of claim 1, wherein the ILO is based on a tank circuit.

9. A controller device that controls the operation of a memory device, the controller device comprising:

an injection-locked oscillator (ILO) having a free-running frequency that is controlled by at least a control value; and

circuitry to determine at least a first control value that corresponds to a phase boundary between two adjacent phase tuning ranges of the ILO.

10. The controller device of claim 9, further comprising circuitry to store the first control value.

11. The controller device of claim 10, further comprising circuitry to determine a second control value that corresponds to a phase difference with respect to a reference phase, wherein the second control value is determined based on the stored first control value.

12. The controller device of claim 11, further comprising circuitry to provide the second control value to the ILO.

13. The controller device of claim 9, wherein the circuitry to determine at least the first control value comprises circuitry to select an injection point of the ILO, wherein the injection point corresponds to one of the two adjacent phase tuning ranges of the ILO.

14. The controller device of claim 13, wherein the circuitry to determine at least the first control value comprises circuitry to sweep the free-running frequency of the ILO until the phase boundary between the two adjacent phase tuning ranges of the ILO is detected.

15. The controller device of claim 9, wherein the ILO is based on a ring oscillator.

16. The controller device of claim 9, wherein the ILO is based on a tank circuit.

17. A method, comprising:

in a circuit comprising an injection-locked oscillator (ILO) having a free-running frequency that is controlled by at least a control value, determining at least a first control value that corresponds to a phase boundary between two adjacent phase tuning ranges of the ILO.

18. The method of claim 17, further comprising storing the first control value.

19. The method of claim 18, further comprising determining a second control value that corresponds to a phase difference with respect to a reference phase, wherein the second control value is determined based on the stored first control value.

20. The method of claim 17, wherein said determining at least the first control value comprises:

injecting an injection signal into an injection point of the ILO that corresponds to one of the two adjacent phase tuning ranges of the ILO; and

modifying the free-running frequency of the ILO until the phase boundary between the two adjacent phase tuning ranges of the ILO is detected.