-----Original Message----- From: cores-bounces at opencores.org [mailto:cores-bounces at opencores.org] On Behalf Of hemanths at dacafe.com Sent: Thursday, February 17, 2005 1:03 PM To: Discussion list about free open source IP cores Subject: RE: [oc] I2C test bench timing violations? Richard, I was trying to use the cordic transformer available in OC which has been developed by you. I was reading the pdf dcoument in it. there for the rectangular to polar conversion block you mention the outputs as begin "16 bit integer and 4 bit fractional". Does this apply to both the Rout and Aout?? If I want the Aout to be b/w -pi to pi in 2's complement form, can I just use the given Aout as it is or do I have to modify the format?? I appreciate any help for the above two questions. thanks, Hemanth ----------------------------------------- Stay ahead of the information curve. Receive EDA news and jobs on your desktop daily. Subscribe today to the EDA CafeNews newsletter. [ http://www10.edacafe.com/nl/newsletter_subscribe.php ] It's informative and essential. _______________________________________________ http://www.opencores.org/mailman/listinfo/cores

Oy, long time ago ....
The particular cordic algorithm you're talking about converges only for
input values in the range -0.5pi to +0.5pi.
To use the full 2pi range you need to mangle the input and output values.
There is a version available that does exactly this. It's included in the
tarball as well ...

The range of the results (i.e. the number of valid bits) depends on the
depth of the pipeline. Larger pipeline, larger dynamic range.
Keep in mind that you need to adjust the output value (the K-factor). The
amount you need to adjust it by is, again, dependant on how deep the
pipeline is.

Hope this answers the question.


Cheers,
Richard

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