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Altera_Forum
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11 years ago

to_float() "right bound of range must be a constant" error

I'm using Quartus 7.2. When trying to compile this piece of code: variable denum : integer; variable num : integer; variable dividend : float (4 downto -27); ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
11 years ago

Here is the user guide for the floating point IP cores. Its updated for the latest version (13.1) but I dont think the float ip cores have really changed in that time. http://www.altera.co.uk/literature/ug/ug_altfp_mfug.pdf

The latest version of the free web edition is available from here: http://www.altera.co.uk/products/software/quartus-ii/web-edition/qts-we-index.html

As for frequency - its really down to your application. If you need to run at 100 MHz you will struggle to get anywhere near that with the floating point library (you may be stuck at <20MHz). With the float IP cores, with enough pipelining, >200MHz should be achieveable.