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Method and apparatus for slew-rate encoded information for transmission

IP.com Disclosure Number: IPCOM000008008D
Publication Date: 2002-May-10
Document File: 4 page(s) / 19K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method and apparatus for slew-rate encoded information for transmission. Benefits include improved performance and improved signal quality.

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Method and apparatus for slew-rate encoded information for transmission

Disclosed is a method and apparatus for slew-rate encoded information for transmission. Benefits include improved performance and improved signal quality.

Description

              The disclosed method encodes multiple bits of information into the slew rate of a signal that is transmitted. The slew rate (slope) of the signal corresponds to a symbol. This symbol is then used as a key to decode the encoded information. 

              Figure 1 shows the encoded slew rate. The slope of the signal encodes the information. The level and edge portion of the signal carries no information but its duration directly affects the symbol transmission rate. Points v1 and v2 are voltage references that the information-carrying signal requires to transition through in order to calculate the slope (slew rate) of the signal.

              Figure 2 shows how the slew-rate of an information-bearing signal maps to a symbol. The number of different symbols that can be represented on the slew depends on:

§         Duration of level

§         Slew rate of edge

§         Slew-rate change detection

              Two bits of information are encoded on the slew of a signal (see Figure 2). One method of implementation is to start a counter when v1 threshold is met, and stop the counter when v2 threshold is met. The counted value is the encoded binary information.

              The receiving logic (see Figure 3) passes threshold v1 for the slew-rate information signal and starts a counter. When v2 threshold is met the counter s...