UVM Ojbect Print

2023-10-31
#UVM #UVM Base #UVM Object
UVM

uvm_object是衍生所有其他UVM相關的data和component的base class。所以uvm_object有一系列通用的function讓衍生的class使用。

Example

範例的是使用 UVM 自動化macro來print變數內容。 Object class 是繼承了 uvm_object ，所以繼承了父類別中的所有功能。在Object class中宣告了一些不同data type的變數，然後用print function印出這些變數。

對於每種不同的資料類型，都有對應的``uvm_field_*` macro讓使用者使用與其data type相對應的macro註冊。UVM_DEFAULT這個FLAG表示這個變數要套用於物件所有預設 UVM 的自動化macro，就是copy、print、compare、record和pack。想知道有哪些FLAG可參考uvm-1.2\docs\html\src\base\uvm_object_globals.svh。

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Object extends uvm_object;
    e_bool   bool;
    bit[3:0] bit_var;
    byte     byte_arr[4];
    int      int_queue[$];
    string   str;

    `uvm_object_utils_begin(Object)
        `uvm_field_enum(e_bool, bool, UVM_DEFAULT)
        `uvm_field_int(bit_var, UVM_DEFAULT)
        `uvm_field_sarray_int(byte_arr, UVM_DEFAULT)
        `uvm_field_queue_int(int_queue, UVM_DEFAULT)
        `uvm_field_string(str, UVM_DEFAULT)
    `uvm_object_utils_end
    function new(string name = "Object");
        super.new(name);
        str = name;
        bit_var = $random;
    endfunction
endclass

接著在base_test裡面產生Object的instance然後用print function印出物件的內容

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class base_test extends uvm_test;
  `uvm_component_utils(base_test)
  function new(string name = "base_test", uvm_component parent = null);
    super.new(name, parent);
  endfunction

  function void build_phase(uvm_phase phase);
    Object obj = Object::type_id::create("obj");
    obj.print();
    // obj.randomize();

  endfunction
endclass

module tb;
  initial begin
    $display("start");
    run_test("base_test");
  end
endmodule

output

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# start
# UVM_INFO @ 0: reporter [RNTST] Running test base_test...
# ---------------------------------------
# Name         Type          Size  Value
# ---------------------------------------
# obj          Object        -     @473
#   bool       e_bool        32    FALSE
#   bit_var    integral      4     'h4
#   byte_arr   sa(integral)  4     -
#     [0]      integral      8     'h0
#     [1]      integral      8     'h0
#     [2]      integral      8     'h0
#     [3]      integral      8     'h0
#   int_queue  da(integral)  0     -
#   str        string        6     Object
# ---------------------------------------

Using do_print()

如果想要客製化自己的print，可以實作do_print function，然後客製化自己想要的格式，但我沒仔細看，就把網頁上的範例簡單試試

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class Object extends uvm_object;
    e_bool   bool;
    bit[3:0] bit_var;
    byte     byte_arr[4];
    int      int_queue[$];
    string   str;

    `uvm_object_utils(Object)
    function new(string name = "Object");
        super.new(name);
        str = name;
        bit_var = $random;
    endfunction

    virtual function void do_print(uvm_printer printer);
      super.do_print(printer);
      printer.print_string("1bool", bool.name());
      printer.print_field("2bit_var", bit_var, $bits(bit_var), UVM_HEX);
      printer.print_string("3str", str);
    endfunction
endclass

output

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# start
# UVM_INFO @ 0: reporter [RNTST] Running test base_test...
# ----------------------------------
# Name        Type      Size  Value
# ----------------------------------
# obj         Object    -     @473
#   1bool     string    5     FALSE
#   2bit_var  integral  4     'h0
#   3str      string    6     Object
# ----------------------------------

Using sprint

UVM object也有sprint function，function的return值是以字串格式傳回格式化的內容。跟print的差別是print就是把object的內容印出來，sprint則是把內容放在return的字串上面，下面的例子是使用`uvm_info印出sprint回傳的字串

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class base_test extends uvm_test;
  `uvm_component_utils(base_test)
  function new(string name = "base_test", uvm_component parent = null);
    super.new(name, parent);
  endfunction

  function void build_phase(uvm_phase phase);
    Object obj = Object::type_id::create("obj");
    // obj.print();
    // obj.randomize();
    `uvm_info(get_type_name(), $sformatf("Ojbect Contents is in below:\n %s", obj.sprint()), UVM_LOW)
  endfunction
endclass

module tb;
  initial begin
    $display("start");
    run_test("base_test");
  end
endmodule

output

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# start
# UVM_INFO @ 0: reporter [RNTST] Running test base_test...
# UVM_INFO .\uvm_object_print.sv(59) @ 0: uvm_test_top [base_test] Ojbect Contents is in below:
#  ---------------------------------------
# Name         Type          Size  Value
# ---------------------------------------
# obj          Object        -     @473
#   bool       e_bool        32    FALSE
#   bit_var    integral      4     'h4
#   byte_arr   sa(integral)  4     -
#     [0]      integral      8     'h0
#     [1]      integral      8     'h0
#     [2]      integral      8     'h0
#     [3]      integral      8     'h0
#   int_queue  da(integral)  0     -
#   str        string        6     Object
# ---------------------------------------