# Calculating the number of MACs in a system

I want to calculate the number of MACs. I am looking for the method.

How would I do it if I know the domain equations from a biquadratic digital filter. I have already calculated the Z domain equations, i know X(z), Y(z) and already calculated my zeros and poles, I also have all the A and B values.

• what do you call a MAC in big O notation? Big MACS – user28715 Jul 9 '19 at 15:53
• why the two $H(z)$ formulas? And, considering you already have a processing block diagram, where's the problem reading the number of multiply-accumulates (per output sample, I'd guess? You're not specifying that.) from the block diagram? – Marcus Müller Jul 9 '19 at 16:27
• Sorry the a,b,c,d,e values from the block diagram are as follows:a=0.39, b=-0.01, c=0.22, d=-0.65, e =0.02 – Gary Hand Jul 9 '19 at 16:46
• you need 5 multiplications and 2 additions. – Ben Jul 9 '19 at 16:51
• I am trying to understand how i calculate the number of MACs the system needs based on the info i have, can you explain what you mean by 5 multiplications and 2 additions? – Gary Hand Jul 9 '19 at 17:44