before it. This is applicable for both constraints and conditional statements. The following example is the same as we saw before except that its constraint has been tweaked to reflect an invertedinsidestatement. classABC;randbit[3:0]m_var;// Inverted inside: Constrain m_var to be outside 3...
constraint c_date{ month inside { [1:12] }; //约束month day inside { [1:31] }; //约束day year inside { [2010:2030] };//约束year } endclassinside是常见的约束运算符,表示变量应该属于某一个值的集合,除非述存在其他约束,否则随机变量在集合重敢值的概率是相等的。 集合里也可以使用变量。ra...
inside操作符 constraint con_name{srcinside {[lo,hi]};//src>=lo && src<=hisrcinside {[lo,$]};//src>=losrcinside {[$,hi]};//src<=hi} ->操作符 constraint con_name{ (condition)->约束;//等同于 if(condition) 约束;} 在顶层打开或关闭约束块 ...
2 inside { some_dynamic_array }; } 相反,如果我们约束数组中不包含值2呢? constraint not_contains_c { !(2 inside { some_dynamic_array }); } 3、约束数组中每个值都是唯一的。 constraint all_elems_unique_c { unique { some_dynamic_array }; } 这个约束非常简短高效,等价于下面这段冗长的代码:...
使用inside运算符产生一个值的集合。 //随机值的集合 rand int c;//随机变量 int lo, hi;//作为上限和下限的非随机变量 constraint c_range{ c_inside{[lo:hi]};// lo<=c且c<=hi } 1. 2. 3. 4. 5. 6. 可以使用$来代表取值范围里的最小值和最大值。
constraint C1 {y inside {[1:10]};} constraint C2 {x < y; } endclass module top; A a1,a2; initial begin a1 = new(); a2 = new(); assert(a1.randomize(y)); // x=2(unchanged state), y=3-10 (random) assert(std::randomize(a2.x,a1.y) with {a2.x > 0; a1.y < a2....
If randomization fails, then the variables retain their original values and are not modified。如过随机化失败(比如说,约束条件无法满足), class trans; rand bit [3:0] data1; randc bit [3:0] data2; bit [7:0] data3; constraint c_data1 { data1 >= 8;} constraint c_data2 { data2 <...
The constraint is disabled by using the constraint_mode method, so on randomization constraint solver will not consider the constraint. class packet; rand bit [3:0] addr; constraint addr_range { addr inside {5,10,15}; } endclass module static_constr; initial begin packet pkt; pkt = new(...
Constraint declared inside the class will get suppressed by inline constraints. class packet; rand bit [3:0] addr; constraint addr_range { soft addr > 6; } endclass module soft_constr; initial begin packet pkt; pkt = new(); repeat(2) begin pkt.randomize() with { addr < 6;}; $disp...
)inside{[1:8]};}endclass//使用foreach产生递增的数组元素的值classAscend;randunitd[10];constraint...