Output bus bit resolution of a digital filter

Hello all,

Does anyone know of a link/web page/article/ that gives the equations to calculating the output databus bit resolution of a digital filter.

I imagine the following factors should be somewhere in the equations:

1. input databus resolution of the digital filter
2. scaling factor of the coeffciients to their binary equivalents
3. DCgain of the FF coeffcicients (if it is an IIR)
4. order of filter, type of filter, number of taps/coeffcients ....
5. Maximum amplification that the filter will allow, for any given frequency

Please advise

-Roger