TLM PORT,IMPORT and EXPORT

[keyur_san88]

Hi,

I am a new learner to UVM.Am very much confused about how to use TLM ports,exports and IMPORTS.And when,Where and why to use ?

[janick]

I hear you.... these classes are named for what they do, from an implementation perspective, not what they are used for from a user perspective. And actually it is not "import" but "imp" for "implementation".

First, I have to ask what are you trying to accomplish, so we can determine which port to use.

If you are using analysis ports, the source uses the "port", the observers use the "imp". If you need to export a port through a higher level component, you use an "export" for the observer and a "port" for the source.

If you can use the TLM2 sockets instead, they are named from a user's perspective (initiator vs target) (socket vs passthru_socket) so you need not mess around with that imp/ex/port confusion.

Avoid using the other TLM1 ports if you can but they work the same as analysis ports.

[keyur_san88]

Thank you Janick.

Actually rigtht now i am more concentrating on TLM1.I got some of the idea that i can connect port to port,export and imp.and export to export and imp.but still confuse about how to connect imp to imp .and i m thinking of a scenario where i need connect two implementation ports.

[uwes]

hi,

i think the model is simple to remember:

1. TLM1 interaction is always 'initiated' at a PORT

2. the started interaction is always handled finally by an "IMP"lementation

3. the path between the starting PORT and the final IMP may contain other "EXPORTS" (which are a simple proxies between PORT and IMP) or PORTS

you can see connection rules

PORT-[PORT|EXPORT,IMP] + EXPORT-[EXPORT|IMP] but NOT IMP-IMP

ps: i know there is a broadcast scenario which allows [EX]PORT-IMP*

could you please explain more of you usage model?

regards

/uwe