Takethe following piece of code as an example:
module test_2 (input [3:0] din, output [4:0] dout);
reg [4:0] dout;
dout[i] = din[i];
The Verific XST (prior to version 13.3) would have given the following warning message for the above piece of code:
"WARNING:HDLCompiler:532 - "test_2.v" Line 10:Index <4> is out of range [3:0] for signal <din>."
Starting from version 13.3 of XST, this warning is modified to an error without any change to the actual information or message as follows:
"ERROR: HDLCompiler:532 - "test_2.v" Line 10: Index <4> is out of range [3:0] for signal <din>."
In the above example, index i (when it reaches 4) will be out-of-range with din [3:0].The HDLCompiler errors out with the above message in similar scenarios, as mentioned in the above example.