uvm_resource_db class usage

[sankey]

HI,

I want to know the usage of "uvm_resource_db" class and also in its different methods there is one argument like scope in which in their example they have provided "*", i am not getting why they have provided it.

If possible please provide me some useful scenario of it !!

Thanks.

[sankey]

HI,

I want to know the usage of "uvm_resource_db" class and also in its different methods there is one argument like scope in which in their example they have provided "*", i am not getting why they have provided it.

If possible please provide me some useful scenario of it !!

Thanks.

Please provide the use of uvm_config_db() also !!

[Roman]

HI,

I want to know the usage of "uvm_resource_db" class and also in its different methods there is one argument like scope in which in their example they have provided "*", i am not getting why they have provided it.

If possible please provide me some useful scenario of it !!

Thanks.

Hi Sankey,

To build highly configurable , reusable testbenches. UVM provides a facility called 'resources' that provides the configuration infrastructure and API.

The resource facility is comprised of polymorphic resource containers, a database for storing those resource containers and a means for locating resources in the database.

We use the resources to supply configuration infomation to a component. the component retrieves a value from the resource pool and uses it to control its topology or behavior.

For example:

following will create a new resource , populates it and inserts it into the resource pool.

uvm_resource_db#（int）::set("roman","top\.aa\..*",2011,this);

we create a new resource whose name is "roman", is visible in the scopes identified by "top\.aa\..*", and has the value of 2011.

The component that retrieves this resource would read the value from the database.

if(!uvm_resource_db#（int）::read_by_name("roman",get_full_name(),value,this))

`uvm_error("WRONG","resource not found in this scope ");

read_by_name() returns a bit that indicates whether or not the lookup succeeded.

The class uvm_resource_db#（T）is a convenience layer on top of the low-level database access classes and methods. it's not instantiated. but contains a collection of static functions that operate resources and resource pool.

Hope to help you.

[Roman]

Please provide the use of uvm_config_db() also !!

The uvm_config_db#(T) class provides a convenience interface on top of the uvm_resource_db to simplify the basic interface that is used for reading and writing into the resource database.

Configuration parameters should be accesed by calling uvm_config_db #(T)::get explicitly from the build_phase method and copying their values to local variables.

class producer extends uvm_component;

...

producer_config config_h;

// Configuration parameters

bit param1 = 0;

int param2 = 0;

string param3;

...

function void build_phase(uvm_phase phase);

super.build_phase(phase);

my_port = new("my_port", this);

begin

if ( uvm_config_db #(producer_config)::get(this, "", "config", config_h) )

begin

param1 = config_h.param1; // Local parameters copied from configuration object

param2 = config_h.param2;

param3 = config_h.param3;

end

end

endfunction

...

endclass

set the values of the configuration parameters from elsewhere, which could be from higher-level components in the test bench, or could be from a specific test. Do do so, a UVM component calls set_config_object from the build method prior to creating the relevant lower-level components:

/////////////////////////////////////

class R_test extends uvm_test;

...

function void build_phase(uvm_phase phase);

super.build_phase(phase);

begin

producer_config config_h = new;

config_h.param1 = 1; // Set test-specific values for configuration parameters

config_h.param2 = 2;

config_h.param3 = 3;

uvm_config_db #(my_agent_config)::set(this, "*.*producer*", "config", config_h);

end

top_h = top::type_id::create("top_h", this);

endfunction

endclass

[sankey]

Hi give me example of uvm_config_db how to used it and how to pass parameter and which file a want to need to make basic testcase... and also i have tried out above example but its not working i got syntex error at uvm_config_db ...

[Roman]

Hi give me example of uvm_config_db how to used it and how to pass parameter and which file a want to need to make basic testcase... and also i have tried out above example but its not working i got syntex error at uvm_config_db ...

Hi Sankey,

I think the example i post above had given the usage for uvm_config_db , but this is just a usage not full codes example.

Pls paste your syntex error and your implementation codes, we could take a look.