Quick Answer: Why Build Phase Is Top Down?

What is an analysis port?

The analysis port is used to perform non-blocking broadcasts of transactions.

It is by components like monitors/drivers to publish transactions to its subscribers, which are typically scoreboards and response/coverage collectors.

For each port, more than one component can be connected..

Why connect phase is bottom up?

Rest other phases are bottom up phases,take the example of connect phase,it is basically used for TLM interconnection between the components and generally its needed to move up the hierarchy as the connections are mostly port to port,port to export and export to export.

Why do we need phases in UVM?

The reason why UVM came up with such phases is because synchronization among all design-testbench was necessary. Using Verilog and VHDL, verification engineers did not have facilities such as clocking block or run phases. … That is the main reason why UVM has different phases.

What is the UVM RAL model why it is required?

UVM RAL as the name suggests, is a high-level object-oriented abstraction layer to access design registers. RAL model mimics the design registers and this entire model is fully configurable. Due to its abstraction behavior, RAL model can be easily migrated from block level to system level.

What is Run_test in UVM?

run_test( ) within tb_top as shown above, is a global task which is responsible for getting a reference to the uvm_root class instance from UVM core services. … The main component that controls simulation in a UVM environment is the uvm_phase class instance.

What are the benefits of using UVM?

UVM also improves reusability through object oriented programming (OOP) features, such as inheritance, and by using override components, which are allowed by polymorphism. These are additional benefits of UVM.

What are the different phases of Uvm_component explain each?

UVM Common PhasesUVM Common PhasesThe common phases are the set of function and task phases that all uvm_components execute together.uvm_check_phaseCheck for any unexpected conditions in the verification environment.uvm_report_phaseReport results of the test.uvm_final_phaseTie up loose ends.6 more rows

What is build phase in UVM?

1) Build Phase: The build phases are executed at the start of the UVM Testbench simulation and their overall purpose is to construct, configure and connect the Testbench component hierarchy. All the build phase methods are functions and therefore execute in zero simulation time.

Can we have a user defined phase in UVM?

Creation of user-defined phases in UVM is a possibility although it may hinder in complete re-usability of the testbench. There are chances for components to go out of sync and cause errors related to null pointer handles. But, in case you decide that you have to use one for your project, keep reading.

What is objection in UVM?

When an objection is raised, UVM testbench structure keeps a count of how many objections it received and decrements the count as other components drop previously raised objections. If you raise an objection and do not drop it, the current phase will never end and simulation would most likely hang.

What is a UVM sequence?

A UVM sequence is a collection of SystemVerilog code which runs to cause “things to happen”. … For example a WRITE_READ_SEQUENCE could generate a random WRITE transaction and send it to the sequencer and driver. The driver will interpret the WRITE transaction payload and cause a write with the specified address and data.

What is the use of Uvm_config_db?

The uvm_config_db is used when hierarchy is important. With the uvm_config_db, the user not only can add an object to the database, but can also specify, with great detail, the level of access to retrieval by specifying the hierarchy. The classic example of uvm_config_db usage is with sharing a virtual interface.

What is the difference between OVM and UVM?

For the most part, OVM == UVM. From OVM, the “O’s” were changed to “U’s” and “tlm*” was changed to “uvm_tlm*”. If you use OVM today, you can migrate to UVM as your projects permit and as your tool chain adapts to small changes.

Why final phase is top down in UVM?

All UVM phases are bottom-up except the build phase which is top down (because the parent components have to be constructed already when the child components are built).

How do I end my UVM test?

By the way to stop the simulation using UVM there is 1 meachanism. It is the objection mechanism. This is the default way to stop a simulation in the operational mode.

What is Uvm_config_db?

The uvm_config_db class provides a convenience interface on top of the uvm_resource_db to simplify the basic interface that is used for configuring uvm_component instances. uvm_config_db. All of the functions in uvm_config_db#(T) are static, so they must be called using the :: operator.

What is difference between Uvm_config_db and Uvm_resource_db?

In particular, uvm_resource_db uses a “last write wins” approach. The uvm_config_db, on the other hand, looks at where things are in the hierarchy up through end_of_elaboration, so “parent wins.” Once you start start_of_simulation, the config_db becomes “last write wins.”