feedback architecture for FIR filter

[Arnab Ghosh]

can anyone please explain what is the use of feedback loop in this implementation ? This is an IEEE paper . I cant understand why we should feed back the previous dataView attachment papsum6.pdf

 

[axcdd]

feedback is used when u have less MAC units then filter length.
eg. 4 tap fir filter
y=x[3]*c[3]+x[2]*c[2] + x[1]*c[1]+x[0]*c[0]
when having only 2 multiplayers available:
ACC=x[3]*c[3]+x[2]*c[2] then
ACC=x[1]*c[1]+x[0]*c[0] + ACC (feedback)

 

[FvM]

I think the term "feedback" may be misleading, I would prefer "serial processing".