Math calculations in VHDL - Page 2

Altera_Forum · ‎10-17-2012

Hi all,

I need a little help with my design, there are a few issues that I'm trying to resolve.

My design flow is as following: A signal is sampled by a 16bit A2D, multiplied by 2 another 16bit signals (which results in 2 32bit signals). After a few manipulations I need to implement a formula that uses those 2 signals with division, multiplication and a few other functions that are calculated using LUTs. The LUTs are designed for a signal normalized to the range of 0 - pi/2. Note that after the formula the signals will be converted to 32bit floating-point signals.

The formula requires some fractional calculations so I'm trying to use the fixed point package by David Bishop but I'm facing a few issues:

1. How am I supposed to convert the 32bit signals (integer) to 32 fixed point numbers?

2. I'm trying to divide the 2 32bit signals - what is the best way to do this? I tried the lpm_divide megafunction but I get a quotient and a remain while I need the whole number (i.e. 5.65 and not only 5).

3. How exactly am I supposed to use the fixed-point package? I have the following libraries, is that enough?

Library ieee;

use ieee.std_logic_1164.all;

use ieee.std_logic_unsigned.all;

use ieee.fixed_float_types.all;

use ieee.fixed_pkg.all;

Thanks in advance, help will be very appreciated.

Altera_Forum · ‎12-03-2013

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Got it, thank you.

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pls publish the code which u hv got