Are there errors with fir compiler, or with me?

:confused:

As use Quartus 8.0 Fir compiler for interpolation fir filter, I found some errors with output of it.

Firstly, when the order of the interpolation is larger than 16, the coefficient generated by software automatically is disordered. For example, the order of the filter is 256 with coefficient c0,c1,...,c255, and the order of interpolation is 32, so there are 32 subfilters, which order is 8, the coefficient of the first one is c0,c32,c64,c96,c128,c160,c192,c224. But in fact, it is NOT.

Secondly, the output of the filter is disordered. When the order of the interpolation is 16, the coefficient is OK, but the output order is disordered. In fact, the output of the filter is d0,d1,...,d15, but now it is d7,d8,...,d15,d0,d1,...,d6.

Are there errors with the software, or with me. Thank you!