FIR Compiler IP Block Bit Settings

[Anonymous]

Hi folks!

We are implementing a chain of FIR filters, all with the config in the attachement but different coefficients!

Sadly after the first FIR filter (if we test with a "chain" of just one filter) we are experiencing an attenuation of approximately factor 32 which would mean that something with the fixed point arithmetics is off by 5 bits. But no matter how I try, I cannot seem to find the mistake ...

Can anybody with some more experience help me spot the hopefully obvious mistake?

Thanks in advance

Yatekii

[bwiec]

It is probably from bit growth in the FIR. The core calculates bit growth based on the data/coef types and also the coefficient values (or worst-case in the case of reloadable coefficients). The core guarantees no overflow via bit growth.