08-14-2019 05:17 AM
i need to subtracte two signal, those have different data types: "first_signal: floating-point data type" ; "second_signal: fixed-point data type".
i am going to prepare a vhdl code to calculate the subtraction of these two inputs. i would like to hear from you and get some suggestion, like what i need to avoid or to take into consideration.
I am very glad to hear from you and thanks in advance.
08-15-2019 11:48 PM - edited 08-15-2019 11:53 PM
good morning drjohsmith
thank you very much for your comment.
so, i have two system doing the same function (multiplication), one is prepared in vhdl code and using no floating-point library (just fixed-point data type). The second system is implemented in cyclone V with ARM proccessor, and the floating point library is available (i will use the single precision - 32 bits). 32 bits precision equivalent to 7 decimal digits.
So, the both systems doing the same operation, have the same results with different data type.
Do you have any suggestions that i can follow to do this kind of comparison and thanks in advance.
08-16-2019 03:02 AM
can I ask how your using a cyclone V on a Xilinx Part ?
08-16-2019 03:26 AM
08-16-2019 04:10 AM
Just a reminder this is a forum run by Xilinx for Xilxin support,
08-16-2019 06:12 AM
Buy a Xilinx chip? That would make it easy. Xilinx has their Floating Point IP core, and Xilinx's Vivado HLS can easily accept both fixed-point and floating-point values, do maths on them, and spit out a result.
At the highest level, the easiest approach here is probably to get the fixed-point values into the PS, convert them to floating-point (easy), and then do the comparison in C code. It'll be easier to get the PS to handle fixed-point than getting the PL to handle floating-point. By far the hardest part is likely to be getting the values into the PS - and you won't get much help for that here, since it'll be manufacturer-specific and everyone here just knows how to do it with Xilinx chips.