IP Library Granted Patent US 8,688,399
Granted Patent B2
US 8,688,399 · App. 13/656,238 · Granted Apr 1, 2014

Strobe-offset control circuit

Inventor: Scott C. Best (Palo Alto, CA)
Assignee: Rambus Inc.
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Quick Facts
Patent No.
US 8,688,399
App. No.
13/656,238
Granted
Apr 1, 2014
Kind
B2
Abstract

A method of operation in a memory controller is disclosed. The method includes receiving a strobe signal having a first phase relationship with respect to first data propagating on a first data line, and a second phase relationship with respect to second data propagating on a second data line. A first sample signal is generated based on the first phase relationship and a second sample signal is generated based on the second phase relationship. The first data signal is received using a first receiver clocked by the first sample signal. The second data signal is received using a second receiver clocked by the second sample signal.

Claims (45)

1. A method of operation in a memory controller, the method comprising:

generating, using a signal generator, a first sample signal based on a first timing relationship between first data and a timing reference signal;

sampling, using a first sampler, the first data in response to the first sample signal;

generating, using the signal generator, a second sample signal based on a second timing relationship between second data and the timing reference signal; and

sampling, using a second sampler, the second data in response to the second sample signal.

2. The method according to claim 1 wherein the timing reference signal is a strobe signal.

3. The method according to claim 2 wherein:

the first timing relationship comprises a phase difference between a first transition associated with the first data and a second transition associated with the strobe signal; and

the second timing relationship comprises a phase difference between a third transition associated with the second data and the second transition.

4. The method according to claim 3 wherein the first and second timing relationships are determined during a calibration mode.

5. The method according to claim 4 wherein during the calibration mode, the first and second timing relationships are adjusted based on detected phase differences between the strobe signal and the first and second data.

6. The method according to claim 1 wherein the first timing relationship is based on applying a first delay to one or both of the timing reference and the first data to produce a relative phase offset between the timing reference and the first data.

7. The method according to claim 6 wherein the second timing relationship is based on applying a second delay to one or both of the timing reference and the second data to produce a relative phase offset between the timing reference and the second data.

8. The method according to claim 7 wherein the delay associated with the first timing relationship is independent of the second delay associated with the second timing relationship.

9. The method according to claim 1 wherein the first and second timing relationships are based on absolute delay associated with the timing reference signal and the first and second data.

10. The method according to claim 1 wherein the first and second timing relationships are based on relative delays between the timing reference signal and the first and second data.

11. A memory controller comprising:

timing circuitry including

a first timing signal generator to generate a first sample signal based on a first timing relationship between first data and a timing reference signal;

a second timing signal generator to generate a second sample signal based on a second timing relationship between second data and the timing reference signal;

sampling circuitry including

a first sampler to sample the first data in response to the first sample signal; and

a second sampler to sample the second data in response to the second sample signal.

12. The memory controller according to claim 11 wherein:

the first timing signal generator includes a first delay circuit to delay a version of the timing reference signal by a predetermined first phase offset; and

the second timing signal generator includes a second delay circuit to delay a second version of the timing reference signal by a predetermined second phase offset.

13. The memory controller according to claim 12 and further comprising:

calibration circuitry to, in a calibration mode, define the predetermined first phase offset and the predetermined second phase offset.

14. The memory controller according to claim 13 wherein the calibration circuitry includes phase detection circuitry to adjust the first and second phase offsets based on detected phase relationships between the timing reference signal and the first and second data.

15. The memory controller according to claim 11 and further comprising:

respective first and second data inputs to receive the first and second data; and

a strobe signal input to receive a strobe signal as the timing reference signal.

16. A method of operation in an integrated circuit, the method comprising:

in a calibration mode,

determining a first timing relationship based on a phase difference between a first transition associated with first receive data and a second transition associated with a timing reference signal that accompanied the first receive data;

determining a second timing relationship based on a phase difference between a second transition associated with second receive data and the second transition associated with the timing reference signal;

in a data transfer mode,

generating, using a signal generator, a first sample signal based on the first timing relationship;

sampling, using a first sampler, the first data in response to the first sample signal;

generating, using the signal generator, a second sample signal based on the second timing relationship; and

sampling, using a second sampler, the second data in response to the second sample signal.

17. The method of claim 16 wherein the first and second timing relationships are based on absolute delay associated with the timing reference signal and the first and second data.

18. The method according to claim 16 wherein the first and second timing relationships are based on relative delays between the timing reference signal and the first and second data.

19. The method according to claim 18 wherein the delay associated with the first timing relationship is independent of the second delay associated with the second timing relationship.

20. The method according to claim 16 wherein the timing reference signal is a strobe signal.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 13, 2023
From: RAMBUS INC.
To: K.MIZRA LLC
Reel/Frame 065229/0338 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 31, 2014
From: BEST, SCOTT C.
To: RAMBUS INC.
Reel/Frame 032567/0453 →
Continuity (5)
Continuation 13276708 · Oct 19, 2011
Continuation 12694251 · Jan 26, 2010
Continuation 11621491 · Jan 9, 2007
Continuation 10923421 · Aug 20, 2004
Related Publication 20130044552A1 · Feb 21, 2013