Ovm reporting

OVM
1

Hi,

I seem to have some conceptual doubts on the ovm reporting.

  1. what really is the arg “string filename” to ovm_report_* meant for?
    This has nothing to do with the actual log file. Is this correct?

  2. to dump a message to a file, do I have to first configure set_report_severity_file/set_report_id_file etc.

An example would really help.

Regards

2

Hi,

  1. what really is the arg “string filename” to ovm_report_* meant for?

It can be used to pass the name of the file containing the source code that issued the call to ovm_report_* to the report handler. There is also an optional line argument that can be used to pass the line number to the report handler too.

  1. to dump a message to a file, do I have to first configure set_report_severity_file/set_report_id_file etc.

Yes - here is an example:

OVM_FILE fd = $fopen("env2.log");  //open log file

//setup environment to send info messages to log file
   env2.set_report_default_file_hier(fd);   
   env2.set_report_severity_action_hier(OVM_INFO,OVM_LOG);

Hope that is enough to give you the idea.

Regards,
Dave

3

Hi,
It can be used to pass the name of the file containing the source code that issued the call to ovm_report_* to the report handler. There is also an optional line argument that can be used to pass the line number to the report handler too.
Yes - here is an example:

OVM_FILE fd = $fopen("env2.log");  //open log file

//setup environment to send info messages to log file
env2.set_report_default_file_hier(fd);   
env2.set_report_severity_action_hier(OVM_INFO,OVM_LOG);

Hope that is enough to give you the idea.
Regards,
Dave

Thanks Dave.

Can I assume that reporting configurations I do are per ovm_component instance and not global. For example, I can set default file name for one instance as log_x and another as log_y.

Regards

4

Hi,

Can I assume that reporting configurations I do are per ovm_component instance and not global. For example, I can set default file name for one instance as log_x and another as log_y.

The set_report_hier methods apply to a component and all of its children. You can use set_report_file methods if you want to set the options for a single component instance.

Regards,
Dave

5

The other Dave here, :D

Use the compiler directives __FILE__ and LINE to pass to ovm_report_*. e.g.

ovm_report_info("CHECK","Just checking here",,`__FILE__,`__LINE);

The Questa GUI will use that information to later trace the message back to is spot the source code.

If you want a setting to be truly global, you need to do the following

_global_reporter.set_report_handler(ovm_top.get_report_handler());
ovm_top.set_report_*_hier(...);

Dave Rich

6

Thanks, Dave & Dave

7

The other Dave here, :D
If you want a setting to be truly global, you need to do the following

_global_reporter.set_report_handler(ovm_top.get_report_handler());
ovm_top.set_report_*_hier(...);

Dave Rich

Hello Dave!

Can you explain me this code.

I take attached code from this forum
http://ovmworld.org/forums/showpost.php?p=2799&postcount=7

add rewrite function build of my_testclass this way

virtual function void build;
      super.build();
      ovm_report_info("", "Called my_test::build");
      // Always use the factory instead of new
      m_env = my_env::type_id::create("m_env",this);
      // lets log to file
      fd = $fopen("log.txt");
      m_env.set_report_default_file_hier(fd);
      _global_reporter.set_report_handler(m_env.get_report_handler());
      m_env.set_report_severity_action_hier(OVM_INFO, OVM_LOG);
      m_env.set_report_severity_action_hier(OVM_ERROR, OVM_LOG);
     //set_global_timeout(1us);
    endfunction: build

but then simulation is finished, there is no m_driver1ovm_report_info message in the log file. Can you tell me there is the problem?

and one more

The set_report_*_hier methods apply to a component and all of its children.

Children in this phrase are all objects inherited from this class or all objects inserted into this class?

Thank you.

8

Generally, I avoid using the terms parent/child when talking about inheritance. I use parent/child when referring to a tree structure of individual objects.

You need to perform set_report_handler before issuing any other set_report functions.

Dave

9

In reply to sharan_basappa:

Hi,

Is there any way by which we can open a file in append mode. I observed that following line opens a file in write mode.
OVM_FILE fd = $fopen(“env2.log”); //open log file

code like
OVM_FILE fd = $fopen(“env2.log”, “w”); //open log file

doesn’t write anything in the file, in fact gives error.
Can we control modes n which files are opened? Similar code does work in simple SV environment but not OVM. Is there something I am missing.

Thanks.

10

In reply to Mandar_Thete:

Can you tell what error you are getting?

Do you have the LRM that explains what the second argument to $fopen should be to open the file in append mode?

11

In reply to dave_59:

Hi,

What I am trying to do is this -

f= $fopen(“errorlog”, “a+”); // 2nd argument gives error as mentioned below
set_report_severity_file(OVM_ERROR, f);
set_report_severity_action(OVM_ERROR, OVM_DISPLAY + OVM_LOG + OVM_COUNT);

Error : src/compatibility/urm_message.sv(494): $fdisplay : Argument 1 is an unknown file descriptor.

I am trying to pull all the error messages in this newly opened file. (I should have been clearer earlier while posting question). Why is $fdisplay function not able to find the FD?

Code works if we do not pass any ‘mode’ argument while opening file.

12

In reply to Mandar_Thete:

How did you declare f?

Also, do you have any `message macros or any other legacy code calling URM? It should not be invoking the compatibility layer unless you have that.

13

In reply to dave_59:

Code works if we do not pass any ‘mode’ argument while opening file.

That seems to suggest that $fopen with MCD (Multi-Channel Descriptor) works fine in your tool, but not with a “fd” (Recall V2K added the FD concept with type as the 2nd argument to $fopen).

Maybe there is a +v2k switch needed in your tool? Which tool do you use? Also try few things:

  1. Use $ferror after the $fopen to see the “fd” is returned properly
  2. Use plain $fdisplay and see if that works
  3. Try “w” mode first to see if that works.

File IO has been a pain with some tools, but not this bad I suppose.

Good Luck
Ajeetha, CVC

14

In reply to ajeetha:

Hi,

I have declared f as int.

I have tried using $ferror and $fdisplay. These work perfectly fine - File gets appended with custom ($fdisplay) messages.(While doing so I comment set_report_severity_file(OVM_ERROR, f) and set_report_severity_action(OVM_ERROR, OVM_DISPLAY + OVM_LOG + OVM_COUNT))

Issue appears only when I use set_report_severity_file and set_report_severity_action. As far as know I am passing required argument to them.

I am using ovm_report_error(“error_id”, “error_msg”) command to raise errors.

Note : As mentioned before, code works when I use $fopen(“filename”); But for every test case file gets overwritten. When I use append mode, I throws errors.

Does that mean, set_report_severity_file and set_report_severity_action do not support append mode?

I believe ovm_report_error is causing this error PROVIDED I have opened file in append mode.

15

In reply to Mandar_Thete:

Mandar,
Spoke to Srini, our CTO on this involved issue as he vaguely recalls it from a customer engagement. He pointed me to the compatibility layer, specifically the code:


// src/compatibility/urm_message.sv 
  if ( msg.m_action & OVM_DISPLAY ) msg.m_destination |= 1;

Perhaps the above code assumed MCD than the modern FD. Can you try removing OVM_DISPLAY in your action to see if that helps?

If you need further assistance, consider creating a simple testcase and share/send across (training@cvcblr.com). Alternatively contact your EDA vendor with a testcase.

Good Luck
Ajeetha, CVC

16

In reply to ajeetha:

Thanks Ajeetha and Dave,

When I remove OVM_DISPLAY, functionality does work (of course we have to give up on messages to be displayed on terminal).

Thanks for the solution. However, I will still go ahead and send the test case to EDA vendor to see if I can get some better picture(will try send to mentioned email as well asap). I will update the outcome of it here as well.

-Mandar

17

In reply to Mandar_Thete:

Hi all,
Please find a working example ready to run, given below…
the same can be ported to uvm using ovm2uvm.pl

refer OVM2UVM | Verification Academy for the details.
tested on ovm 2.1.2 and uvm 1.1d using the above method.

Feel free to provide your valuable feedbacks.

import ovm_pkg::*;

module display;
initial begin
run_test(“my_test”);
end

initial #100 ovm_top.stop_request();

endmodule:display

class my_test extends ovm_test;
`ovm_component_utils(my_test)

int fh,fh1;

function new (string name , ovm_component parent);
super.new(name, parent);
endfunction:new

virtual task run();
fh = $fopen (“my_test_fh.log”,“w”); // opening two text files
fh1= $fopen (“my_test_fh1.log”,“w”);

set_report_default_file(fh1); // setting default write file as fh1

`ovm_info(get_name(),“Hello world”,OVM_LOW) // this will be printed only to terminal/ simulation log
// since ‘set_report_severity_action’ is not yet set

$fdisplay(fh,“fdisplay - Hello world”); // will be written irrespective of ‘set_report_*’ setting

set_report_severity_action(OVM_INFO, OVM_LOG); // redirecting `ovm_info ony to text file

ovm_info(get_name(),"My world",OVM_LOW) // will be in text file my_test_fh1.log $fdisplay(fh,"fdisplay - My world"); set_report_default_file(fh); // setting default to fh, here after all ovm_info woll be
// directed to fh
// instead of fh1

set_report_severity_action(OVM_INFO, OVM_LOG | OVM_DISPLAY ); // setting `ovm_info to be directed to my_test_fh.log
// and to terminal/ simulation log

$fdisplay(fh1,“fdisplay1 - My world”);
`ovm_info(get_name(),"My last world :-) ",OVM_LOW) // will be in text file my_test_fh.log
// and in terminal/ simulation log

$fclose(fh);
$fclose(fh1);
endtask:run
endclass:my_test

regards,
Sachin Scaria