A circuit to detect pin layer reversal including an input circuit to receive
an
input signal having a first portion to indicate a pin layer reversal and having
a second portion to indicate a servo sync mark, a first servo sync mark detector
for detecting a positive servo sync mark from the input signal, a second servo
sync mark detector for detecting a negative servo sync mark from the input signal,
and a circuit responsive to the positive servo sync mark and the negative servo
sync mark to generate a signal to indicate if the servo sync mark has been reversed
and to generate a signal to indicate the pin layer reversal.
