The FIR filter is equipped with 4-tap, 6-bits dual input and 7-bits dual output, designed to fine-tune the PR4 equalization of a Read/Write channel for digital tape. It has a filter coefficient adaptation loop, able to optimize the 6 bits taps coefficients.

Features:

• 6 bits signed input, paired( 2 samples per clock)
  
• 7 bits signed coefficients
  
• 7 bits signed output, paired ( 2 samples per clock )
  
• 42 MHz operation in 0.18mm CMOS technology
  
• 4 taps, 5 coefficients ( middle one fixed )
  
• independently adapted coefficients using LMS algoritm with error sign and input amplitude
  
• programmable adaptation rate
  
• the coefficients can be adapted symetrical or independently
  
• every coefficient has an enable bit for adaptation