FPGA, SoC, And CPLD Boards And Kits
FPGA Evaluation and Development Kits
6367 Discussions

Simulating by ModelSIM on quartus|| 9.0 - XOR function bus_signals error in verilog file

Savino
Beginner
448 Views

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.

Labels (1)
0 Kudos
1 Solution
ShengN_Intel
Employee
342 Views

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


View solution in original post

0 Kudos
5 Replies
sstrell
Honored Contributor III
374 Views

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.

0 Kudos
ShengN_Intel
Employee
358 Views

Hi,


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


0 Kudos
Savino
Beginner
353 Views

Hi, 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)

0 Kudos
ShengN_Intel
Employee
343 Views

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


0 Kudos
Savino
Beginner
283 Views

okay, tks for fdk

0 Kudos
Reply