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OVM SEQUENCE 5


Sequencer Registration Macros




Sequence Registration Macros does the following
1) Implements get_type_name method.
2) Implements create() method.
3) Registers with the factory.
4) Implements the static get_type() method.
5) Implements the virtual get_object_type() method.
6) Registers the sequence type with the sequencer type.
7) Defines p_sequencer variable. p_sequencer is a handle to its sequencer.
8) Implements m_set_p_sequencer() method.

If there are no local variables, then use following macro


`ovm_sequence_utils(TYPE_NAME,SQR_TYPE_NAME)



If there are local variables in sequence, then use macro


`ovm_sequence_utils_begin(TYPE_NAME,SQR_TYPE_NAME)
`ovm_field_* macro invocations here
`ovm_sequence_utils_end



Macros `ovm_field_* are used for define utility methods.
These `ovm_field_* macros are discussed in
OVM_TRANSACTION


Example to demonstrate the usage of the above macros:



class seq_mul extends ovm_sequence #(instruction);

rand integer num_inst ;
instruction req;

constraint num_c { num_inst inside { 3,5,7 }; };

`ovm_sequence_utils_begin(seq_mul,instruction_sequencer)
`ovm_field_int(num_inst, OVM_ALL_ON)
`ovm_sequence_utils_end

function new(string name="seq_mul");
super.new(name);
endfunction


virtual task body();
ovm_report_info(get_full_name(),
$psprintf("Num of transactions %d",num_inst),OVM_LOW);
repeat(num_inst) begin
`ovm_do_with(req, { inst == MUL; });
end
endtask

endclass

(S)Download the example


ovm_sequence_9.tar
Browse the code in ovm_sequence_9.tar


(S)Command to sun the simulation


Your_tool_simulation_command +incdir+path_to_ovm testcase.sv



(S)Log

OVM_INFO @ 0: reporter [RNTST] Running test ...
OVM_INFO @ 0: reporter [sequencer.seq_mul] Num of transactions 5
0: Driving Instruction MUL
10: Driving Instruction MUL
20: Driving Instruction MUL
30: Driving Instruction MUL
40: Driving Instruction MUL


Setting Sequence Members:



set_config_* can be used only for the components not for the sequences.
By using configuration you can change the variables inside components only not in sequences.

But there is a workaround to this problem.

Sequence has handle name called p_sequencer which is pointing the Sequencer on which it is running.
Sequencer is a component , so get_config_* methods are implemented for it.
So from the sequence, using the sequencer get_config_* methods, sequence members can be updated if the variable is configured.

When using set_config_* , path to the variable should be sequencer name, as we are using the sequencer get_config_* method.

Following method demonstrates how this can be done:


(S)Sequence:


1) num_inst is a integer variables which can be updated.
2) In the body method, call the get_config_int() method to get the integer value if num_inst is configured from testcase.


class seq_mul extends ovm_sequence #(instruction);

integer num_inst = 4;
instruction req;

`ovm_sequence_utils_begin(seq_mul,instruction_sequencer)
`ovm_field_int(num_inst, OVM_ALL_ON)
`ovm_sequence_utils_end

function new(string name="seq_mul");
super.new(name);
endfunction


virtual task body();

void'(p_sequencer.get_config_int("num_inst",num_inst));

ovm_report_info(get_full_name(),
$psprintf("Num of transactions %d",num_inst),OVM_LOW);
repeat(num_inst) begin
`ovm_do_with(req, { inst == MUL; });
end
endtask

endclass


(S)Testcase:


From the testcase, using the set_config_int() method, configure the num_inst to 3.
The instance path argument should be the sequencer path name.



module test;


instruction_sequencer sequencer;
instruction_driver driver;

initial begin
set_config_string("sequencer", "default_sequence", "seq_mul");
set_config_int("sequencer", "num_inst",3);
sequencer = new("sequencer", null);
sequencer.build();
driver = new("driver", null);
driver.build();

driver.seq_item_port.connect(sequencer.seq_item_export);
sequencer.print();
fork
begin
run_test();
sequencer.start_default_sequence();
end
#3000 global_stop_request();
join
end

endmodule


(S)Download the example


ovm_sequence_10.tar
Browse the code in ovm_sequence_10.tar


(S)Command to sun the simulation


Your_tool_simulation_command +incdir+path_to_ovm testcase.sv



(S)Log

OVM_INFO @ 0: reporter [RNTST] Running test ...
OVM_INFO @ 0: reporter [sequencer.seq_mul] Num of transactions 3
0: Driving Instruction MUL
10: Driving Instruction MUL
20: Driving Instruction MUL



From the above log we can see that seq_mul.num_inst value is 3.




Index
Introduction
Ovm Testbench
Ovm Reporting
Ovm Transaction
Ovm Factory
Ovm Sequence 1
Ovm Sequence 2
Ovm Sequence 3
Ovm Sequence 4
Ovm Sequence 5
Ovm Sequence 6
Ovm Configuration

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