COMMUNICATION CHANNEL CALIBRATION WITH NONVOLATILE PARAMETER STORE FOR RECOVERY

• US 20110235727A1
• Filed: 06/02/2011
• Published: 09/29/2011
• Est. Priority Date: 05/28/2004
• Status: Active Grant

• Current Assignee: Rambus Inc.
• Original Assignee: Rambus Inc.
• Inventors: YEUNG, PHILIP, Perego, Richard E., Best, Scott C.
• Granted Patent: US 8,488,686 B2
• Time in Patent Office: Days
• US Class Current: 375/259
• CPC Class Codes: G11C 2029/4402 Internal storage of test result, quality data, chip identification, repair information
• CPC Class Codes: G11C 29/02 Detection or location of defective auxiliary circuits, e.g. defective refresh counters
• CPC Class Codes: G11C 29/022 in I/O circuitry
• CPC Class Codes: G11C 29/028 with adaption or trimming of parameters
• CPC Class Codes: G11C 7/20 Memory cell initialisation circuits, e.g. when powering up or down, memory clear, latent image memory
• CPC Class Codes: H04L 25/49 using code conversion at the transmitter; using predistortion; using insertion of idle bits for obtaining a desired frequency spectrum; using three or more amplitude levels ; Baseband coding techniques specific to data transmission systems spectral shaping H04L25/03828
• CPC Class Codes: H04L 5/1438 Negotiation of transmission parameters prior to communication modified according to link quality H04L1/0001
• CPC Class Codes: H04L 7/0004 Initialisation of the receiver H04L7/0075 and H04L7/10 take precedence
• CPC Class Codes: H04L 7/0091 Transmitter details
• CPC Class Codes: H04L 7/10 Arrangements for initial synchronisation

Abstract

A communication channel is operated by storing a calibrated parameter value in nonvolatile memory during manufacturing, testing, or during a first operation of the device. Upon starting operation of the communication channel in the field, the calibrated parameter value is obtained from the nonvolatile memory, and used in applying an operating parameter of the communication channel. After applying the operating parameter, communication is initiated on a communication channel. The operating parameter can be adjusted to account for drift immediately after starting up, or periodically. The process of starting operation in the field includes power up events after a power management operation. In embodiments where one component includes memory, steps can be taken prior to a power management operation using the communication channel, such as transferring calibration patterns to be used in calibration procedures.

Claims

1. A method of operation in a system including a communication channel, the communication channel including a first component having a transmitter, a second component having a receiver and a communication link coupling the first and second components, comprising:

upon a power up event, accessing a parameter value stored in nonvolatile memory, wherein the parameter value is determined using a first calibration process, and setting a value for an operating parameter of the communication channel using the calibrated parameter value;

communicating data on the communication channel using the operating parameter; and

adjusting the value for the operating parameter to account for changes in environmental conditions which have an effect on the communication channel using a second calibration process that includes transmitting a calibration pattern from the first component and receiving the calibration pattern in the second component after setting the operating parameter using the calibrated parameter value.