Signaling accommodation

• US 7,099,786 B2
• Filed: 02/24/2005
• Issued: 08/29/2006
• Est. Priority Date: 02/14/2002
• Status: Expired due to Term

• Current Assignee: Rambus Inc.
• Original Assignee: Rambus Inc.
• Inventors: Nguyen, Huy M., Lau, Benedict C.
• Primary Examiner(s): Hoff, Marc S.
• Assistant Examiner(s): Charioui, Mohamed
• Application Number:
  US11/064,925
• Publication Number:
  US 20050154547A1
• Time in Patent Office: 551 Days
• Field of Search: 702/46, 702/57, 702/58, 702/62, 702/64, 702/65, 702/69, 702/71, 702/79, 702/80, 702/90, 702/106, 702/111, 702/117, 702/118, 702/120, 702/122, 702/188, 702/191, 702/193, 327/108, 327/541, 326/21, 326/66
• US Class Current: 702/62
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C

Abstract

A receiving unit may implement voltage compensation using a parameters table, an analog calibration component, and/or a digital calibration component. In certain implementation(s), an integrated circuit may include a voltage driver that modifies a supplied compensated voltage based on a feedback signal. The feedback signal may be produced responsive to a distributed voltage version of the compensated voltage, to a received data signal, and to a comparison involving an expected data value. In other implementation(s), a parameters table may be initialized by storing calibration values in entries in association with respective multiple identifications of multiple external points. In still other implementation(s), a particular calibration value of multiple calibration values may be ascertained, with the particular calibration value associated with a particular external point; the particular calibration value may be activated; and data from the particular external point may be received using the particular calibration value. Other implementations are also described.

Claims

1. A method for calibrating reception by a receiving unit, the method, comprising:

sending a first data pattern from the receiving unit to a first external point;

instructing the first external point to transmit the first data pattern back to the receiving unit;

determining a first common mode voltage of a first data signal carrying the first data pattern back to the receiving unit;

determining a first calibration value based on the action of determining a first common mode voltage of a first data signal; and

storing the first calibration value in association with a first identification of the first external point.

2. The method as recited in claim 1, further comprising:

sending a second data pattern to a second external point;

instructing the second external point to transmit the second data pattern back;

determining a second common mode voltage of a second data signal carrying the second data pattern back;

determining a second calibration value based on the action of determining a second common mode voltage of a second data signal; and

storing the second calibration value in association with a second identification of the second external point.

3. The method as recited in claim 2, wherein the first data pattern is identical to the second data pattern.

4. The method as recited in claim 2, wherein the first data pattern is different from the second data pattern.

5. The method as recited in claim 2, further comprising:

determining a need to request data from the second external point;

ascertaining that the second calibration value is associated with the second external point;

activating the second calibration value;

instructing the second external point to transmit the data; and

receiving the needed data from the second external point using the second calibration value.

6. The method as recited in claim 1, wherein the action of sending a first data pattern to a first external point comprises the action of sending the first data pattern to a memory storage module.

7. The method as recited in claim 1, wherein the method is performed by a memory controller.

8. The method as recited in claim 1, wherein the action of determining a first calibration value based on the action of determining a first common mode voltage of a first data signal comprises the action of determining the first calibration value such that the first calibration value may be utilized by a voltage driver to adjust a compensated voltage to improve a voltage margin usable for receiving future data signals from the first external point.

9. The method as recited in claim 1, wherein the action of determining a first common mode voltage of a first data signal carrying the first data pattern back comprises at least one of the following actions:

determining the first common mode voltage of the first data signal using at least a sampler; and

determining the first common mode voltage of the first data signal using at least a comparison unit, control logic, and a feedback signal.

10. The method as recited in claim 1, wherein the first calibration value comprises a voltage compensation value.

11. The method as recited in claim 1, further comprising:

activating the first calibration value;

instructing the first external point to transmit requested data; and

receiving the requested data from the first external point using the first calibration value.

12. A method for initializing and operating a system having a receiving unit with receiving functionality, comprising:

executing an initialization, the initialization comprising;

sending at least one data pattern from the receiving unit to a plurality of external points;

instructing the plurality of external points to transmit the at least one data pattern back to the receiving unit in a respective plurality of signals;

determining a respective plurality of calibration values for the plurality of external points responsive to receipt of the respective plurality of signals; and

storing the respective plurality of calibration values in association with a respective plurality of identifications of the plurality of external points; and

implementing an operational phase, the operational phase comprising;

determining that data is to be received from a particular external point of the plurality of external points;

ascertaining a particular calibration value of the plurality of calibration values, the particular calibration value associated with the particular external point;

activating the particular calibration value; and

receiving the data from the particular external point using the particular calibration value.

13. The method as recited in claim 12, wherein the system comprises a memory system.

14. The method as recited in claim 12, wherein the system comprises a memory controller, and the plurality of external points comprise a plurality of memory storage modules.

15. The method as recited in claim 12, wherein the actions of the implementing an operational phase action are repeated for multiple external points of the plurality of external points.

16. The method as recited in claim 12, wherein the actions of the executing an initialization action are repeated for at least one external point of the plurality of external points.

17. A method for receiving data, comprising:

determining a need to request first data from a first external point;

ascertaining that a first calibration value is associated with the first external point;

activating the first calibration value;

requesting the first external point to transmit the first data; and

receiving the first data from the first external point using the first calibration value.

18. The method as recited in claim 17, further comprising:

determining a need to request second data from a second external point;

ascertaining that a second calibration value is associated with the second external point;

activating the second calibration value;

requesting the second external point to transmit the second data; and

receiving the second data from the second external point using the second calibration value.

19. The method as recited in claim 17, wherein the action of ascertaining that a first calibration value is associated with the first external point comprises the action of accessing a parameters table at an entry having an identification that is associated with the first external point, the entry including the first calibration value.

20. The method as recited in claim 17, wherein the action of activating the first calibration value comprises the action of loading a register with the first calibration value.

21. The method as recited in claim 17, wherein the action of receiving the first data from the first external point using the first calibration value comprises the action of adjusting a voltage that is used to interpret received signaling responsive to the first calibration value.

22. A method for voltage compensation, comprising:

determining a first compensation value based, at least partly, on a first signal received from a first external point;

storing the first compensation value in association with a first identification of the first external point;

determining a second compensation value based, at least partly, on a second signal received from a second external point;

storing the second compensation value in association with a second identification of the second external point;

extracting the second compensation value;

activating the second compensation value; and

receiving data from the second external point using the second compensation value to adjust a voltage.

23. The method as recited in claim 22, wherein:

the action of storing the first compensation value in association with a first identification of the first external point further comprises the action of storing the first compensation value in a parameters data structure; and

the action of storing the second compensation value in association with a second identification of the second external point further comprises the action of storing the second compensation value in the parameters data structure.

24. An integrated circuit configured to perform actions comprising:

determining a need to request first data from a first external point;

ascertaining that a first calibration value is associated with the first external point from a parameters data structure;

activating the first calibration value;

requesting the first external point to transmit the first data;

receiving the first data from the first external point using the first calibration value;

determining a need to request second data from a second external point;

ascertaining that a second calibration value is associated with the second external point from the parameters data structure;

activating the second calibration value;

requesting the second external point to transmit the second data; and

receiving the second data from the second external point using the second calibration value.