How to constraint the sequence in Squence Lib

[jsree]

Hi

I coded sequence lib as follows

class simple_seq_lib extends uvm_sequence_library#(my_trans);

`uvm_object_utils(simple_seq_lib)

`uvm_sequence_library_utils(simple_seq_lib)

`uvm_add_to_seq_lib(nomacro_seq, simple_seq_lib);

`uvm_add_to_seq_lib(directed_seq, simple_seq_lib);

`uvm_add_to_seq_lib(super_seq, simple_seq_lib);

// Weights only apply when using UVM_SEQ_LIB_RAND mode

constraint select_rand_dist {

select_rand dist {

0 := 70, // nomacro_seq

1 := 20, // directed_seq

2 := 10 // super_seq

};

}

function new(string name="");

super.new(name);

init_sequence_library();

endfunction

endclass

in the testcase coded as follows

class third_seq_test extends demo_base_test;

typedef uvm_config_db#(uvm_object_wrapper) phase_cfg;

pkt_lib::simple_seq_lib my_seq_lib;

`uvm_component_utils(third_seq_test)

function new(string name = "third_seq_test", uvm_component parent);

super.new(name,parent);

endfunction : new

virtual function void build_phase(uvm_phase phase);

my_seq_lib = new("my_seq_lib");

void'(my_seq_lib.randomize());

uvm_config_db#(uvm_sequence_base)::set(this, "demo_tb0.tm.simple_tx_agent.sequencer.main_phase",

"default_sequence",

my_seq_lib);

// Create the testbench

super.build_phase(phase);

endfunction

endclass : third_seq_test

in the testcase I like to constraint some field in nomacro_seq (sequence item 0), Please let me know how to code the same

Thanks in Advance

Jay

[jadec]

One way is to subclass that sequence (and add the constraint in the subclass) then use the factory to replace it.

[jsree]

Hi Jadec

Still it is not very clear, could you please post sample code.

Thanks

Jay

[jadec]

From examples/simple/factory/test.sv:

class mypacket extends packet;

constraint ct10 { addr >= 0 && addr <= 10; }

//Use the macro in a class to implement factory registration along with other

//utilities (create, get_type_name).

`uvm_object_utils(mypacket)

endclass

initial begin

packet::type_id::set_type_override(mypacket::get_type());

You can do the same thing for your sequence type.

[jsree]

HI Jadec

Thanks. Let me review this examples more and figure it out it helps me to constaint the sequce inside a existing sequence lib.

Jay