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Altera_Forum
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14 years ago

VHDL Math Real & Quartus

I've been using the VHDL package ieee.math_real to declare parameters, the idea being to condense as much information in a design file as possible. in particular, for fixed point operations in feedba...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

I remember having that divide problem once also, but I forgot when ... I don't divide many 'real's though, but recently I did this: 

ARCZ => integer( ( real(PI_TIMES_TWO) * ARCTAN( 2.0 ** (-(i))) / MATH_2_PI)) ,

This is in Quartus II 11.1sp1.

I tried your code 
	variable RecipFactor :   real := ROUND((2.0**15)*(1.0/(SQRT(3.0))));
and got no other warning than:

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Warning (10542): VHDL Variable Declaration warning at math_real.vhd(2373): used initial value expression for variable "RECIPROCAL" because variable was never assigned a value

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but that is a long time annoyance ...