SigmaStudio 3.5: FP Filter Table Generator behaviour
Hi,
I tried to use the Fixed-Point Table Generator in Sigma Studio 3.5 build 7 Rev 912 (== latest release).
Please have a look at the attached screenshot. Is this the correct behaviour when I try to generate filter coefficients?
I don't think so ;-)
Why is a Q1.15 FP value uncompatible? If this FP data format is allowed to enter by the tool, it shall generate the coefficients.
So, I would like to rank this behaviour as an error/bug.
BR,
Andreas
Hi Andreas,
Several of the SigmaStudio software engineers are currently on business trips overseas, so I can't get a quick response to this question. I have entered it in our bug tracking system and alerted the responsible engineers. I will let you know when I get a response.
Here's a response from the software team:
I see what is the problem. The numeric text boxes are not updating accordingly. If you pay close attention to the format being used, you'll see that the input is 1.15. This is incompatible with SigmaDSP because the parameter RAM is 24 bits, so this should should be 1.23. Currently we're not handling that exception when the text-in box is set to a format other than 24 bits. I will change this in such a way that it always sends a 24 bit format instead of 16.
Another update:
Ok. The error is now handled and fixed. What is actually happening is that the coefficient values becomes greater than the format could allow. When an unsupported format is entered, it will then display an error explaining why. This bug fix will be on our next 3.6.2 beta release.
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