Forum Discussion
New ContributorSimulating by ModelSIM on quartus|| 9.0 - XOR function bus_signals error in verilog file
Good evening everyone, for several hours I have been running into a problem using quartus|| 9.0 and ModelSim.
I have created a very simple project with a bus input and a bus output, and an XOR function inside. The program synthesis is successful and so is the simulation. Unfortunately, as soon as I try to simulate the program via ModelSIM an error appears. Basically:
- given the program written and compiled with a .bdf file
- I create the .hdl file (so I delete the .bdf file)
- as soon as I launch the RTL simulation, a syntax error appears in the file automatically created by quartus|| as follows:
assign out = in[29:0] ^ {in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in}[30];
if I try to perform the XOR operation between non-bus data (single data) I have no error. It seems that the XOR function between multiple data such as data buses generates this error. Is there a solution?
I attach the project.
Hi Savino,
I misunderstood the situation. As mentioned by sstrell, the input must be same width. Using same width will be no problem.
You're using different width, that's why causing the bug.
Thanks,
Regards,
Sheng
5 Replies
sstrellSuper Contributor
An XOR between a bus and a single signal makes no sense. The bus widths must match to perform a bit-by-bit XOR operation.
ShengN_alteraHi,
Please change this assign out = in[29:0] ^ {in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in,in}[30]; to this assign out = in[29:0] ^ in[30];
Thanks,
Regards,
Sheng
SavinoHi, I tried all the combination without succes and at the end i used more xor gate for each single data, like attached and i fixed the issue but if is possible do the xor operation in one shot for me is better (like at beginning working with bus data)
- ShengN_altera
Hi Savino,
I misunderstood the situation. As mentioned by sstrell, the input must be same width. Using same width will be no problem.
You're using different width, that's why causing the bug.
Thanks,
Regards,
Sheng
- Savino
okay, tks for fdk
