Why does the Fixed Point Advisor show a Trigonometric function as unsupported when using CORDIC approximation?
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Hello,
The Trigonometric Function in Simulink shows that fixed point data type is supported "only when Approximation method is CORDIC". However, when I use a block in my model with CORDIC approximation and I run the Fixed Point advisor, the third task, "Address Unsupported Blocks" fails, with the failing block being the Trigonometric function, and a suggestion to replace with a lookup table. Thanks.
1 Comment
Kaustubha Govind
on 20 Jul 2012
What version of MATLAB are you using? Are you referring to the documentation installed with your version, or from the web? I suspect that fixed-point support may have been added for the Trignometric block in a fairly recent release.
Answers (3)
Kaustubha Govind
on 20 Jul 2012
Edited: Kaustubha Govind
on 20 Jul 2012
What version of MATLAB are you using? Are you referring to the documentation installed with your version, or from the web? Fixed-point support for the Trignometric block was added in R2010a. Also, only the 'sin', 'cos', 'sincos' and 'cos+jsin' functions appear to be supported.
0 Comments
Ali
on 24 Jul 2012
2 Comments
Kaustubha Govind
on 24 Jul 2012
Which function have you selected? If it is indeed one of the supported sin, cos, sincos or cos+jsin functions, I would recommend contacting MathWorks Tech Support to see if this is a bug in Fixed-Point Advisor.
Rafael
on 1 Mar 2013
Hello, I am having the same problem on MATLAB R2012b, and it is quite easy to reproduce. Just go to the link on the help for trigonometric functions http://www.mathworks.com/help/simulink/slref/trigonometricfunction.html and open the link under sincos Function with Fixed-Point Input example, it will open the model with this example, then use the Fixed Point Advisor and it will fail marking this block as unsupported. Has a solution been found? Should each of the people that runs into this problem contact MathWorks Tech Support directly?
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