#971 vvp_process.c: Assertion failed: number_is_immediate

[Austin Garrard]

iverilog crashes on Windows 7 Home Premium 64-bit with the command given below and attached file(IdealMemory.v). Windows indicates that "ivl.exe has stopped working". Installed with iverilog-0.9.7_setup.

Command:
C:\Users\Austin\spring15\csce350\project2>iverilog IdealMemory.v
Assertion failed: number_is_immediate(rword_idx, IMM_WID, 0), file ../../verilog-0.9.7/tgt-vvp/vvp_process.c, line 1256

[Austin Garrard]

The command executes successfully after removing the assign keyword from line 22 in IdealMemory.v. The issue also appears to exist when iverilog is installed on Ubuntu 14.04 via apt-get:

$iverilog IdealMemory.v
ivl: vvp_process.c:1256: force_link_rval: Assertion `number_is_immediate(rword_idx, 32, 0)' failed.

[Cary R.]

This is also failing for the development branch so I'm switching this bug to development. It is unlikely this will be fixed in V0.9 unless it is a trivial fix that is easily back ported since we plan to release V10 fairly soon.

[Martin Whitaker]

This is another manifestation of bug #605 - Icarus doesn't properly support variable expressions on the RHS of a procedural continuous assignment. I've converted the assert to a "sorry" message in the development branch.

With this fix, your code should now work. But you would get a better model of an asynchronous RAM (and avoid the "sorry" message) if you used a normal continuous assignment instead of a procedural one (think about what triggers re-evaluation of the assignment).

[Martin Whitaker]

I've also added the "sorry" messages to the v0.9 branch.The underlying problem is covered by bug #605, so I'm going to close this as fixed.

[Arnab Sanyal]

Hi,
I am using Icarus Verilog version 0.9.7 (v097), and my operating system is Ubuntu 16.04. I am reading a 8 x 8 rgb (red - green - blue) bitmap image from a bin file and changing the colourspace to yCoCg (yellow - chromium orange - chromium green) using a fast adder that I named KoggeStone. The code reads the pixel values from a bin file and writes to another. Note that when I try to compile the code I get a similar error like Mr Garrard has reported. Strangely if I remove the assign keyword from line 31 the code works just fine. Please help me here.

  Thanks in advance
  ps - I installed iverilog via apt-get

[Stephen Williams]

Why do you even have the "assign" keyword there in the first place? It looks
to me like you are just using the for loop to collect the output and write
it to
an output file. The "assign" is not needed for that situation.

On Mon, Oct 10, 2016 at 5:44 PM, Arnab Sanyal lonewolf1898@users.sf.net
wrote:

Hi,
I am using Icarus Verilog version 0.9.7 (v0_9_7), and my operating system
is Ubuntu 16.04. I am reading a 8 x 8 rgb (red - green - blue) bitmap image
from a bin file and changing the colourspace to yCoCg (yellow - chromium
orange - chromium green) using a fast adder that I named KoggeStone. The
code reads the pixel values from a bin file and writes to another. Note
that when I try to compile the code I get a similar error like Mr Garrard
https://sourceforge.net/p/iverilog/bugs/971/#6fc7 has reported.
Strangely if I remove the assign keyword from line 31 the code works
just fine. Please help me here.

Thanks in advance

Attachments:

• colourSpaceTransform.v
  https://sourceforge.net/p/iverilog/bugs/_discuss/thread/527ffd1b/cf61/attachment/colourSpaceTransform.v
  (805 Bytes; text/x-verilog)

---

• [bugs:#971] https://sourceforge.net/p/iverilog/bugs/971/
  vvp_process.c: Assertion failed: number_is_immediate*

Status: closed-fixed
Group: devel
Created: Thu Apr 23, 2015 04:40 PM UTC by Austin Garrard
Last Updated: Sat Apr 25, 2015 12:24 PM UTC
Owner: nobody
Attachments:

• IdealMemory.v
  https://sourceforge.net/p/iverilog/bugs/971/attachment/IdealMemory.v
  (1.7 kB; application/octet-stream)

iverilog crashes on Windows 7 Home Premium 64-bit with the command given
below and attached file(IdealMemory.v). Windows indicates that "ivl.exe has
stopped working". Installed with iverilog-0.9.7_setup.

Command:
C:\Users\Austin\spring15\csce350\project2>iverilog IdealMemory.v
Assertion failed: number_is_immediate(rword_idx, IMM_WID, 0), file
../../verilog-0.9.7/tgt-vvp/vvp_process.c, line 1256

---

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--
Steve Williams "The woods are lovely, dark and deep.
steve@icarus.com steveicarus@gmail.com But I have promises
to keep,
http://www.icarus.com and lines to code before I sleep,
http://www.picturel.com And lines to code before I sleep."

[Martin Whitaker]

This is a different bug to the original report - a different assertion is failing. However, this bug is also fixed in the current release of Icarus Verilog (v10.1), which outputs a suitable error message instead. I would strongly recommend updating to the current release - v0.9 has many known bugs, and is no longer being maintained.

Note that a procedural continuous assignment to an array word is not legal Verilog (and questionably legal in SystemVerilog). But as Steve has said, for what you are trying to do, an ordinary procedural assignment (i.e removing the assign keyword) will suffice.