Receiver to recover data encoded in a serial communication channel
AssigneeGenesis Microchip Inc.
InventorAlexander Julian Eglit
Life of this patent
Estimating the term…
Abstract
A receiver to recover data encoded at high speed in a signal over a serial communication channel. A static phase determination circuit indicates whether the signal is early, late or neutral relative to a sampling clock. The sampling clock is used to oversample the signal to generate multiple samples. A token analyzer examines the transitions around a current symbol to determine any short term phase shifts of the boundaries between symbols. The short term phase shifts and the static phase together may be used to accurately select the samples representing the symbols without requiring extensive processing.
Claims33
A method of recovering a plurality of symbols transmitted over a serial communication channel in the form of a signal, said method comprising:
- (a) receiving said signal;
- (b) over sampling said signal to generate a plurality of samples corresponding to each of said plurality of symbols;
- (c) generating a sampling clock signal, wherein said sampling clock signal controls said over sampling of (b);
- (d) generating a plurality of transition indicators, wherein each transition indicator indicates the presence of a transition in value between two successive samples;
- (e) determining a static phase status representing a long term phase shift of said signal relative to said sampling clock signal, wherein said long term phase shift of said signal is determined based on many prior samples corresponding to a plurality of prior symbols;
- (f) examining a plurality of transition indicators corresponding to a few symbols including a current symbol to determine any short term phase shift of boundaries between symbols around said current symbol;
- and
- (g) selecting a sample corresponding to said current symbol according to said static phase status and said short term phase shift,
- wherein the selection based on said short term phase shift enables the sample corresponding to said current symbol to be selected accurately, and
- wherein the selection based on said static phase status enables th processing to be minimized in said selection.
A circuit to recover a plurality of symbols encoded in a signal on a serial communication channel, said circuit comprising:
- a clock generator to generate a sampling clock signal;
- an analog to digital converter (ADC) to oversample said signal to generate a plurality of samples corresponding to each of said plurality of symbols, wherein said ADC over samples under the control of said sampling clock signal;
- a transition detector to generate a plurality of transition indicators, wherein each transition indicator indicates the presence of a transition in value between two successive samples;
- a static phase determination circuit to determine a static phase status representing a long term phase shift of said signal relative to said sampling clock signal, wherein said long term phase shift of said signal is determined based on many prior samples corresponding to a plurality of prior symbols;
- and
- a tokens analyzer to examine a plurality of transition indicators corresponding to a few symbols including a current symbol to determine any short term phase shift of boundaries between symbols around said current symbol, said token analyzer to determine which sample represents said current symbol according to said long term phase shift and said short term phase shift;
- and
- a samples selector to select said sample determined by said token analyzer as representing said current symbol,
- wherein the selection based on said term phase shift enables the sample representing said current symbol to be selected accurately, and
- wherein the selection based on said static phase status enables the processing to be minimized in said selection.
A circuit to recover a plurality of symbols encoded in a signal on a serial communication channel, said circuit comprising:
- receiving means for receiving said signal;
- over sampling means for over sampling said signal to generate a plurality of samples corresponding to each of said plurality of symbols;
- first generating means for generating a sampling clock signal, wherein said sampling clock signal controls said over sampling means;
- second generating means for generating a plurality of transition indicators, wherein each transition indicator indicates the presence of a transition in value between two successive samples;
- determination means for determining a static phase status representing a long term phase shift of said signal relative to said sampling clock signal, wherein said long term phase shift of said signal is determined based on many prior samples corresponding to a plurality of prior symbols;
- examination means for examining a plurality of transition indicators corresponding to a few symbols including a current symbol to determine any short term phase shift of boundaries between symbols around said current symbol;
- and
- selection means for selecting a sample from the samples corresponding to said current symbol according to said status and said short term phase shift,
- wherein the selection based on said term phase shift enables the sample corresponding to said current symbol to be selected accurately, and
- wherein the selection based on said phase status enables the processing to be minimized in said selection.
Dependencies are inferred from the claim text.