CCS C Software and Maintenance Offers
FAQFAQ   FAQForum Help   FAQOfficial CCS Support   SearchSearch  RegisterRegister 

ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

CCS does not monitor this forum on a regular basis.

Please do not post bug reports on this forum. Send them to support@ccsinfo.com

Question Relating to CIC filters

 
Post new topic   Reply to topic    CCS Forum Index -> General CCS C Discussion
View previous topic :: View next topic  
Author Message
cbarberis



Joined: 01 Oct 2003
Posts: 172
Location: Punta Gorda, Florida USA

View user's profile Send private message Send e-mail

Question Relating to CIC filters
PostPosted: Sat Nov 07, 2009 2:50 pm     Reply with quote

Hello,

I am interested in applying a CIC (Cascaded Integrator-Comb) filter algorithm on a PIC micro. I looked at some info on the web. I found much of it somewhat esoteric and not as clear as I would like, in order to implement my own code. Most of the stuff I found was in the VHDL language which I do not use or understand that well. I was wondering if any of you have any C code snippets that actually implement the CIC filter functions, or if you can point the way to such information.

I am aware that the past October issue of Circuit Cellar did have an article on this subject, however it clearly did not answer my needs.
FvM



Joined: 27 Aug 2008
Posts: 2337
Location: Germany

View user's profile Send private message

PostPosted: Sun Nov 08, 2009 2:16 am     Reply with quote

By design, the word length of a CIC filter is different in individual stages and possibly exceeds the size of the data types provided by a C compiler (typically int32 with 8-bit compilers). It's easy, to achieve a parameterizable (in decimation ratio, order and input/output word length) CIC filter design for FPGA, but for a uP, a full-featured macro assembler would be needed.

Did you calculate the required word lengths for your application?

P.S.: A first order CIC decimator isn't but a simple boxcar averager. You don't need to understand CIC theory to implement it.
Display posts from previous:   
Post new topic   Reply to topic    CCS Forum Index -> General CCS C Discussion All times are GMT - 6 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group