Patent ID: 8228975

Claim:
In a link partner using a plurality of voltage gain taps, a method for zeroing pre and post-tap settings, the method comprising: providing a link partner (LP) transmitter having a signal input, a plurality of parallel selectable voltage gain taps connected to the signal input, including a non-delayed pre-tap, a center tap with a delay of one unit, and a post-tap with a delay of 2 units, and a network-connected output to supply the sum of the taps; a network-connected local device (LD) choosing an LP tap selected from the group consisting of the pre-tap and the post-tap; the LD choosing a zero gain setting for the selected LP tap; determining the current polarity of the selected tap; in a first iteration, the LD directing the LP to decrease the absolute value of the difference between the selected tap gain setting and the zero setting by 1 step; if a zero limit signal is not received by the LD, directing the LP to maximally increase the center tap gain setting until a maximum/minimum limit signal is received, where a zero limit signal is associated with a zero tap setting, and where a maximum/minimum limit signal is associated with a maximum or minimum tap setting; and, continuing the iterations until a zero limit signal is returned in response to the LD directing the LP to decrease the difference between the selected tap gain setting and the zero setting; wherein determining the current polarity of the selected tap includes: directing the LP to maximally increase the center tap gain setting until a maximum/minimum limit signal is received; directing the LP to move the gain setting of the selected tap one step with respect to a first polarity; and, if a zero limit signal is not received, determining that the first polarity is in the direction of the zero setting.