US Patent 7337380 Eye width characterization mechanism

An eye width characterization mechanism determines a pass setting of a sampling phase positioned within an eye width of received data. The sampling phase is incremented in a first direction from the pass setting until the sampling phase is outside the eye width of the received data. The sampling phase is then incremented in an opposite direction of the first direction starting again from the pass setting until the sampling phase is outside the eye width of the received data. The number of the sampling phase increments in the first direction is added to the number of the sampling phase increments in the opposite direction to characterize the eye width of the received data.