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Hi,

I have a function (basicaly implements a LUT) something like the following:```
function integer gen_lut;
input integer addr;
localparam SOME_CONSTANT = 418.39; // Gets calculated at runtime.
localparam D0 = 0.785398163 * SOME_CONSTANT;
localparam D1 = 0.463647609 * SOME_CONSTANT;
...
begin
case (addr)
0: gen_lut = D0;
1: gen_lut = D1;
...
endcase
end
endfunction
```

The thing is I need to convert **d0, d1, ...**from real type to integer at elaboration time to use it later in design. I've tried using system function $rtoi, $floor but Quartus complains:

**error (10174): verilog hdl unsupported feature error at top.v(54): system function "$floor" is not supported for synthesis**Then I've tried implementing a constant function, since I already have log2 function implemented and it works, floor that would take real number and output a integer like so:

```
function integer floor;
input real x;
integer int_part;
begin
int_part = x;
if (int_part > x) begin floor = int_part - 1; end
else begin floor = int_part; end
end
endfunction
```

And the tool complains again: **error (10172): verilog hdl unsupported feature error at const_functions.sv(21): real variable data type values are not supported.**IMHO, this is just ridiculous. I am not even trying to synthesise real values I just want to convert them to integer at elaboration time. Does Quartus even have any kind of support for real data types? I mean even Xillinx ISE and Icarus Verilog have these features supported and have no problem synthesizing. Is there a workaround this problem? I would still like to keep real numbers in the code for easier parametrization. P.S. I saw a similar thread that was posted in 2008, so these features havent been implemented for almost 10 years??? Come on, its not like the whole IDE needs to be re-implemented...

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I've found one possible workaround, how to round real data type down to nearest integer:

1) Create a constant function that will convert real to nearest integer (up or down):```
function integer rtoi;
input integer x;
begin
rtoi = x;
end
endfunction
```

2) Create a macro that will round real down to integer: ``define FLOOR(x) ((rtoi(x) > x) ? rtoi(x) - 1 : rtoi(x))`

3) Use the macro: ```
localparam real R_TEST = 0.785398163 * SOME_CONSTANT;
integer floor_int = `FLOOR(R_TEST);
```

Best regards!
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