I'm just doing a small project about creating noise using FPGAs chips. I can do white noise(uniform distribution). But when I use IIR filter to make white noise become pink noise, I couldn't get the right result. May anybody help me out or please give me advises for this stuff? I have taken the coefficients poles and zeros at firstpr.com.au/dsp/pink-noise to create IIR filter. I implemented these using VHDL language. Below is my code. Thanks for helping.