Please let me know how to use scoreboard across two instances of an
env. I've created two scoreboards-- one, to add what i transmitted and
another to add what i received in an env.Now i've created two instances
of it and the two env's are binded such a way that the output of env
is an input to env.
Pls let me know how should i proceed to check a packet i've transmitted
in one env with that in received scoreboard in env.
Thanks in Advance...
Prabhuk, I assume that you have an instance of the monitor for
capturing transactions across the shared i/f between your 2 envs. So
that monitor should be used to forward transactions to the 2 scorebards
in your 2 envs. If the monitor is instantiated in the envs themselves,
then you'll need to find a way to disable one of them so that only 1
monitor is talking to both scoreboards.
What exactly are you checking between the 2 envs, just that the top-level signals are correctly connected between the 2 devices?
Thank You Joseph,
The env consists of a bfm which is driving a packet on a serial line
and a monitor which is collecting packet
on the serial line. So, i binded the two instances of this env such a
way that the output of one env instance is connected to input of
Meanwhile, I'll try by implementing the monitor independently as you said...
Hi Prabhu,From my experience, there is no need to change your VE design by implementing the monitor outside the environment. Sometimes it is even necessary, e.g. when creating an interface eVC that typically has a monitor instantiated within the environment and you want to check it by cross-connecting two instances and simulate them. This way you will end up with a monitor in each environment instance and it seems to me that this is exactly what you are doing.If so, I would suggest the following:1) Provide hooks in your monitor when a packet is received/transmittedThis provides the flexibility to change the behavior of scoreboarding when your environment is integrated in a larger environment (e.g. system-level) or when using layered verification environments. You may then choose to disable scoreboarding, change its behavior, or even use a system-level scoreboard according to your requirements. This behavior can be set by extending the monitor instance through the hooks provided.2) Instantiatiate your scoreboards separately from the rest of the environmentThis is helpful in system-level verification or layered environment where you may have multiple instances of your environment running and you may want to place scoreboards only in strategic locations or even use a totally different scoreboard. Of course, you will have to provide a basic scoreboard unit as part of your environment.3) Use separate configuration files according to the verification scenarioDoing so will allow you to specify the scoreboarding instantiation and functionality you wish to have from a block-level up to a system-level verification scenario with the maximum level of code reuse and the least amount of changes.4) Provide some sort of synchronizationThere is a potential problem with this configuration, when the monitor from one end will see a packet transmitted and the monitor from the other end will see a packet received at the same time. For example:At time X:Env's BFM will start transmitting a frameAt time X+Y:Env's monitor will detect a frame transmitted and try to push it on the scoreboardEnv's monitor will detect a frame received and try to compare it against the scoreboardDepending on the order of execution, Env's compare might run first, resulting in an empty scoreboard compare. So it is a good idea to sometimes delay the compare by one cycle, if this is permissible by the specification, or provide some sort of syncronization between the two.This of course is mostly the case when cross-connecting two environment instances together. Usually, there is a delay between when the packet is transmitted and when it is received on the other end.The eRM Developer Manual offers quite a few guidelines on scoreboards, including the ones mentioned above at Section 9.3, "Adding Scoreboards".Hope that helps!Regards,--Iraklis.
Thank you very much for providing me a solution.
I've used ur suggestions and able to make my scoreboard work.
Thanks again for providing me very useful information and analysis of the problem.