be determined by register settings or based on the detected maximum values of the coefficients in general the middle coefficient should have the largest value if this is not the case a phase error is introduced and other coefficients have to be scaled in fig5 the scaling is indicated by the multiplier following the overflow control 86 in addition phase information is favorably obtained by comparing the highest absolute coefficient value with its coefficient number a constant group delay caused by the filtering always gives the maximum coefficient value at the same position for an optimum filter coefficient set the middle tap has the highest value the obtained information is passed to the host control as a phase warning either as a flag e g phase off on optimum or as a position identifier coeff0 coeff1 coeff2 coeff3 the mu logic 74 in the lms update block 7 is provided for the coefficient update weight which is favorably larger during the beginning of the adaptation process than during normal operation a possible implementation of the mu logic 74 is depicted in fig7 the operation is simplified and concentrates on only a few coefficients typically the middle tap of the linear filter has the highest coefficient value in the symmetric seven tap example this is the coefficient c3 a noise free adaptation has the odd numbered coefficient as the next highest value but due to the possibility of phase distortion it might also be c2 the coefficient locations in the filter and lms operation are indicated above in equation 2 the coefficients are filtered e g by.