HIGH SPEED SIGNALING SYSTEM WITH ADAPTIVE TRANSMIT PRE-EMPHASIS

• US 20100117706A1
• Filed: 01/25/2010
• Published: 05/13/2010
• Est. Priority Date: 04/09/2003
• Status: Active Grant

• Current Assignee: K.Mizra LLC
• Original Assignee: Rambus Inc.
• Inventors: Stojanovic, Vladimir M., Alon, Elad, Horowitz, Mark A., Bessios, Anthony, Chen, Fred F., Ho, Andrew C. C.
• Granted Patent: US 8,183,887 B2
• Time in Patent Office: Days
• US Class Current: 327/306
• CPC Class Codes: H04B 1/04 Circuits
• CPC Class Codes: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence
• CPC Class Codes: H04B 2001/0416 having gain or transmission power control
• CPC Class Codes: H04L 2025/03363 Multilevel H04L2025/03369 takes precedence
• CPC Class Codes: H04L 2025/03802 Signalling on the reverse channel
• CPC Class Codes: H04L 25/025 using least-mean-square [LMS] method
• CPC Class Codes: H04L 25/028 Arrangements specific to the transmitter end
• CPC Class Codes: H04L 25/0282 Provision for current-mode coupling
• CPC Class Codes: H04L 25/03019 adaptive, i.e. capable of adjustment during data reception
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end
• CPC Class Codes: H04L 25/03885 adaptive
• CPC Class Codes: H04L 25/061 providing hard decisions only; arrangements for tracking or suppressing unwanted low frequency components, e.g. removal of dc offset removal of dc offset in coupling arrangements H04L25/029, H04L25/0296
• 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 25/4917 using multilevel codes

Abstract

A high-speed signaling system with adaptive transmit pre-emphasis. A transmit circuit has a plurality of output drivers to output a first signal onto a signal path. A receive circuit is coupled to receive the first signal via the signal path and configured to generate an indication of whether the first signal exceeds a threshold level. A first threshold control circuit is coupled to receive the indication from the receive circuit and configured to adjust the threshold level according to whether the first signal exceeds the threshold level. A drive strength control circuit is coupled to receive the indication from the receive circuit and configured to adjust a drive strength of at least one output driver of the plurality of output drivers according to whether the first signal exceeds the threshold level.

Claims

1. A method of operation within a signaling system, the method comprising:

sampling a first signal in a first sampling circuit to determine whether the first signal exceeds a first threshold;

sampling the first signal in a second sampling circuit to determine whether the first signal exceeds a second threshold;

adjusting a drive strength of at least one output driver circuit used to generate the first signal based, at least in part, on whether the first signal exceeds the first and second thresholds;

adjusting the second threshold based, at least in part, on whether the first signal exceeds the second threshold,

wherein adjusting the second threshold occurs independent of adjusting the drive strength.