What is the use of transport_dbg and what is the difference between b_tansport and transport_dbg

[ARI]

Hello Everyone,

Could anyone please help me to understand the use cases of transport_dbg and when to use it. Is it mandatory to have implementation of tranport_dbg in target side? How to bypass transport_dbg and use only b_transport.

Thanks
ARI

[Eyck]

transport_dbg is similar to b_transport but without timing and the target is not allowed to call wait (similar to nb_transport_*). It is used to do debugg accesses, e.g. when using a target debugger in a virtual platform. Accesses via transport_dbg shoul be transparrent to the simulation itself. E.g. the simulation should behave the same way no matter if a register is  read via transport_dbg or not.

[David Black]

transport_dbg is used to examine and modify conditions in a simulation. A better name for it would have been, transport_debug.

transport_dbg can also be used to do things such as initialize a memory to setup conditions for a test. Obviously, this does affect simulation.

b_transport is typically used for "loosely-timed" modeling used when simulation performance is more important than timing accuracy. This contrasts with the more intense nb_transport_* pair, which are used for "approximately-timed" simulations (where timing accuracy is more important than simulation performance).