How to measure distance between two data

--- Quote Start ---

sorry kaz . i didn't undersatand that .if you remember that distance is output ,i make a signal instead of output but it every clk increment the accum.

could you plz illustrate.

--- Quote End ---

You can have copy of your output before it escapes as internal signal or you can leave it as it is and use a module for summing.

either way the signal vout that I posted sometime ago is now handy to indicate a sample is active since output data may stay for many clocks.