How do you start a sequence in UVM?

Logic to generate and send the sequence_item will be written inside the body() method of the sequence. The handshake between the sequence, sequencer and driver to send the sequence_item is given below….Starting The Sequence:

Method Call Description
req.randomize() This method is to randomize the sequence_item

How does UVM test start?

A test is usually started within testbench top by a task called run_test . This global task should be supplied with the name of user-defined UVM test that needs to be started. If the argument to run_test is blank, it is necessary to specify the testname via command-line options to the simulator using +UVM_TESTNAME .

What is Start_item and Finish_item in UVM?

start_item() will tell the sequencer that your sequence is available for arbitration by the sequencer. When it returns, your sequence should then set the variables in your sequence_item to the required values (i.e. by randomization or manual methods). finish_item() will then send the sequence_item to the driver.

What is M_sequencer and p_sequencer in UVM?

m_sequencer is the generic uvm_sequencer pointer. it will always exist for the uvm_sequence and is initialized when the sequence is started. p_sequencer is a typed-specific sequencer pointer, created by registering the sequence to the sequencer using macros.

What is the difference between Uvm_do and Uvm_do_with?

`uvm_do_with This is the same as `uvm_do except that the constraint block in the 2nd argument is applied to the item or sequence in a randomize with statement before execution.

What is the difference between Uvm_do and Uvm_send?

The main difference is that `uvm_send will NOT create or randomize while `uvm_do will do both.

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.

What are UVM phases?

UVM Phases are predefined virtual function / tasks defined in UVM component which are supposed to be populated by classes extending from UVM component. These pre-defined virtual methods give each class (extended from UVM component) in the TB a common understanding of what should be executed in each phase.

What is TLM port in UVM?

The TLM Port is used to send the transactions. TLM Ports has unidirectional and bidirectional ports. A port can be connected to any compatible port, export, or imp port.

What is the difference between new () and create?

It seems to me that the primary differences between these two scenarios are: The object used in Object. create() actually forms the prototype of the new object, whereas in the new Function() from the declared properties/functions do not form the prototype.

What is Uvm_sequence_item?

Summary. uvm_sequence_item. The base class for user-defined sequence items and also the base class for the uvm_sequence class. Class Hierarchy.

What is the difference between new () and create in UVM?

create() is factory construction. You are delegating new() to the factory – the factory looks for overrides and replaces construction of your class with some other derived class. You should always use create() rather than using new() for classes registered with the factory.

What is a sequence in UVM?

A sequence generates a series of sequence_item’s and sends it to the driver via sequencer, Sequence is written by extending the uvm_sequence. a sequence is parameterized with the type of sequence_item, this defines the type of the item sequence that will send/receive to/from the driver. the sequence has handle req and rsp of mem_seq_item.

How to start a sequence in UVM testbench?

As far as I know, there are 2 ways of starting a sequence in UVM testbench. 1. Starting a sequence with default_sequence (implicit) 2. Starting a sequence with start method (explicit) I see many people recommend using the start method to start a sequence, but I am not sure why. Can anyone help me with this? Thanks.

Does UVM start_item call send_request to the sequencer?

from the start_item launched by a sequence, I landed in uvm_base_sequence.svh file of UVM source code. Everything is fine in start_item as per my understanding but I don’t see start_item calling send_request to the sequencer. This is where the sequence item is actually sent to the sequencer. The start_item ends after calling pre_do method.

What are the methods associated with UVM_sequence?

There are Methods, macros and pre-defined callbacks associated with uvm_sequence. Users can define the methods (task or function) to pre-defined callbacks. these methods will get executed automatically upon calling the start of the sequence.