Integrated circuit having a clock deskew circuit that includes an injection-locked oscillator

• US 9,564,912 B2
• Filed: 01/07/2016
• Issued: 02/07/2017
• Est. Priority Date: 03/03/2011
• Status: Active Grant

• Current Assignee: Rambus Inc.
• Original Assignee: Rambus Inc.
• Inventors: Aleksi, Marko, Leibowitz, Brian S.
• Primary Examiner(s): Le, Toan
• Application Number:
  US14/990,443
• Publication Number:
  US 20160226504A1
• Time in Patent Office: 397 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. An integrated circuit (IC), comprising:

at least one injection-locked oscillator (ILO), wherein the ILO has multiple injection points, and a free-running frequency that that can be modified by using a control signal;

an injection circuit to inject an injection signal into an injection point of the ILO based on a selection signal; and

a phase controller circuit to (1) determine an injection point and a free-running frequency based on a target phase difference with respect to a reference phase, (2) generate and provide the selection signal to the injection circuit based on the determined injection point, and (3) generate and provide the control signal to the ILO based on the determined free-running frequency.

2. The IC of claim 1, wherein the phase controller determines the injection point by (1) determining a phase tuning range that includes the target phase difference, and (2) determining the injection point that corresponds to the determined phase tuning range.

3. The IC of claim 2, wherein the phase controller determines the free-running frequency based on a difference between a boundary of the determined phase tuning range and the target phase difference.

4. The IC of claim 1, wherein the phase controller generates the control signal based on a set of control values, wherein each control value corresponds to a phase boundary between two adjacent phase tuning ranges of the ILO.

5. The IC of claim 4, further comprising calibration circuitry to determine the set of control values.

6. The IC of claim 1, wherein the ILO is based on a ring oscillator.

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

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

at least one injection-locked oscillator (ILO), wherein the ILO has multiple injection points, and a free-running frequency that can be modified by using a control signal;

an injection circuit to inject an injection signal into an injection point of the ILO based on a selection signal, wherein the injection signal is based on an input clock signal; and

a phase controller circuit to (1) determine an injection point and a free-running frequency based on a target phase difference with respect to a reference phase, (2) generate and provide the selection signal to the injection circuit based on the determined injection point, and (3) generate and provide the control signal to the ILO based on the determined free-running frequency.

9. The controller device of claim 8, wherein the phase controller determines the injection point by (1) determining a phase tuning range that includes the target phase difference, and (2) determining the injection point that corresponds to the determined phase tuning range.

10. The controller device of claim 9, wherein the phase controller determines the free-running frequency based on a difference between a boundary of the determined phase tuning range and the target phase difference.

11. The controller device of claim 8, wherein the phase controller generates the control signal based on a set of control values, wherein each control value corresponds to a phase boundary between two adjacent phase tuning ranges of the ILO.

12. The controller device of claim 11, further comprising calibration circuitry to determine the set of control values.

13. The controller device of claim 8, wherein the ILO is based on a ring oscillator.

14. The controller device of claim 8, wherein the ILO is based on a tank circuit.

15. A method, comprising:

determining an injection point of an injection-locked oscillator (ILO) and a free-running frequency of the ILO based on a target phase difference with respect to a reference phase, wherein the ILO has multiple injection points, and wherein the free-running frequency of the ILO can be modified by using a control signal;

generating and providing a selection signal to an injection circuit based on the determined injection point, wherein the injection circuit injects an injection signal into the determined injection point of the ILO based on the selection signal; and

generating and providing the control signal to the ILO based on the determined free-running frequency.

16. The method of claim 15, wherein determining the injection point comprises:

(1) determining a phase tuning range that includes the target phase difference, and (2) determining the injection point that corresponds to the determined phase tuning range.

17. The method of claim 16, wherein the free-running frequency is determined based on a difference between a boundary of the determined phase tuning range and the target phase difference.

18. The method of claim 15, wherein the control signal is generated based on a set of control values, wherein each control value corresponds to a phase boundary between two adjacent phase tuning ranges of the ILO.

19. The method of claim 15, wherein the ILO is based on a ring oscillator.

20. The method of claim 15, wherein the ILO is based on a tank circuit.