Sequence Override by using set_type_override_by_name call

OVM
1 
function void build();
  ovm_factory f;
  f=ovm_factory::get();
  f.set_type_override_by_name("sequence_1","sequence_2");
endfunction  //coded in Test Build function

I have tried overriding the above sequence1 by sequence2. But once the test runs it not happening. Still my sequence1 is being used by the subsequences. please give me a solution. I am new to writing test cases

// sequence_1 is coded in a separate package,eg ., apb_seq_pkg as follows,
class sequence_1 extends apb_seq_pkg::apb_base_seq;
`ovm_sequence_utils(sequence_1, ovm_sequencer)

function new();
super.new();
endfunction

task body();
write_reg(data,status,reg_name,dev_name);
endtask

function void print_cfg();
endfunction
endclass

// sequence_2 is coded below the test itself,
function void build(); //part of test build function alone
ovm_factory f;
f=ovm_factory::get();
f.set_type_override_by_name(“sequence_1”,“sequence_2”);
endfunction

class sequence_2 extends apb_seq_pkg::sequence_1;
`ovm_sequence_utils(sequence_2, ovm_sequencer)

function new();
super.new();
endfunction

task body();
// write_reg(data,status,reg_name,dev_name); //basically i need to disable this write so i am trying to do sequence override. The apb_seq_pkg(sequence_1) is a softlink so i need to do overrride from test only to disable the write. The sequence is called in subsequence through the test.
endtask

function void print_cfg();
endfunction

endclass

This is not working for me. The register write is happening anyway. please help me on this. I am new to ovm.

2

In reply to Arun_Rajha:

Can you show the code where you construct sequence_1?

3

In reply to dave_59:

// sequence_1 is coded in a separate package,eg ., apb_seq_pkg as follows,
class sequence_1 extends apb_seq_pkg::apb_base_seq;
`ovm_sequence_utils(sequence_1, ovm_sequencer)

function new();
super.new();
endfunction

task body();
write_reg(data,status,reg_name,dev_name);
endtask

function void print_cfg();
endfunction
endclass

// sequence_2 is coded below the test itself,
function void build(); //part of test build function alone
ovm_factory f;
f=ovm_factory::get();
f.set_type_override_by_name(“sequence_1”,“sequence_2”);
endfunction

class sequence_2 extends apb_seq_pkg::sequence_1;
`ovm_sequence_utils(sequence_2, ovm_sequencer)

function new();
super.new();
endfunction

task body();
// write_reg(data,status,reg_name,dev_name); //basically i need to disable this write so i am trying to do sequence override. The apb_seq_pkg(sequence_1) is a softlink so i need to do overrride from test only to disable the write. The sequence is called in subsequence through the test.
endtask

function void print_cfg();
endfunction

endclass

This is not working for me. The register write is happening anyway. please help me on this. I am new to ov

4

In reply to Arun_Rajha:

You just posted the exact same code as your original question, the declarations for sequence_1 and _2. Where do you call the constructor before starting the sequence? Are you calling new() instead of create()?

5

In reply to dave_59:
Yes i understand now what you were asking before,
i have used `ovm_do_with(sequence_1, { m_write==local::m_write}); to call the sequence_1 in another sequence named mptb_ack_seq.

But I am not using new() or create() here instead i am directly calling this(ovm_do_with) without registering to the factory. So basically i am not registering the object in the factory. That is reason i am not able to override the sequence from my test. Correct me if i am wrong.