Kevin wrote: > This part. > Two poles of LPF each with 8 shift bits per pole settles to about 93% > in 1100 iterations. > especially since shifting by 8 bits is particularly trivial, > and 2 x 8 bits is a lot of random noise attenuation. There are a lot of statements in there, so again it's not clear what specifically you are asking about. I guess the only choice is to start at the beginning. The "two poles of LPF" means two low pass filters concatenated. This would be like two RC filters with a buffer in between them. Better answers require better questions. ****************************************************************** Embed Inc, Littleton Massachusetts, (978) 742-9014. #1 PIC consultant in 2004 program year. http://www.embedinc.com/products -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist