Method and apparatus for multi-stage equalization for reading data from storage media

A method for improving equalization when reading data from a storage medium, the method comprising:

• at a first data path:
• decoding, at a first data path using a first decoder, data output from at least one first finite impulse response (FIR) filter;
• and
• adjusting, using first FIR adaptation circuitry, a first FIR coefficient for the at least one first FIR filter;
• and
• at a second data path:
• adjusting, using second FIR adaptation circuitry, a second FIR coefficient to reach an FIR coefficient for at least one second FIR filter that achieves a target minimum number of errors, wherein the second FIR adaptation circuitry reaches the FIR coefficient that achieves the target minimum number of errors faster than the first FIR adaptation circuitry;
• and
• decoding, using a second decoder, data output by at least one second FIR filter.

An apparatus for improving equalization when reading data from a storage medium, the system comprising:

• at a first data path:
• means for decoding data output from at least one first finite impulse response (FIR) filter;
• and
• means for adjusting a first FIR coefficient for the at least one first FIR filter;
• and
• at a second data path:
• means for adjusting a second FIR coefficient to reach an FIR coefficient for at least one second FIR filter that achieves a target minimum number of errors, wherein the means for adjusting the second FIR coefficient reaches the FIR coefficient that achieves the target minimum number of errors faster than the means for adjusting the first FIR coefficient;
• and
• means for decoding data output by at least one second FIR filter.