【日更计划097】数字IC基础题【SV部分】

//<object>.constraint_mode(0) :: 关闭对象中的所有约束
//<constraint>.constraint_mode(0) :: 选择性关闭某一个约束
class  ABC;
    rand int length;
    rand  byte SA;
    constraint c_length { length inside [1:64];}
    constraint c_sa {SA inside [1:16];}
endclass ABC abc = new();
abc.constraint_mode(0) // 关闭所有约束
abc.c_length.constraint_mode(0) // 只关闭约束c_length

class  Packet;
    rand bit[31:0] addr;
    constraint c_addr { addr inside [0:100];}
endclass

Packet p = new();
p.c_addr.constraint_mode(0);
p.randomize with {addr > 200;};

class  dynamic_array;
    rand unsigned int abc[];
endclass

constraint c_abc_len {
    abc.size() < 10;
    foreach (abc[i])
        abc[i] < 10;
}

class array_abc;
    rand unsigned int  myarray[];
endclass

constraint  c_abc_val {
    myarray.size inside { [10:16] };
    foreach (myarray[i])
        if (i>0) myarray[i] < myarray[i-1];
}

class TestClass;
    rand bit[3:0] my_array[];//dynamic array of bit[3:0]
endclass

initial begin
 for (int j=0; j<3; j++) begin
     fork
         automatic int result;
         begin
             result= j*j;
             $display("Thread=%0d value=%0d", j, value);
         end
     join_none
     wait
     fork;
 end
end