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...
constraint常见用法rand bit [7:0] data; // 随机变量 rand bit [3:0] addr; // 随机变量 rand bit [7:0] data_array[10]; // 随机数组 constraint c_data_addr { data inside {[0:100]}; // data的取值范围是0到100 addr dist {0
module tb6; class packet_a; rand int length; constraint cstr {soft length inside {[5:15]};} endclass class packet_b extends packet_a; //constraint cstr{ length inside {[10:20]};}//与父类同名会覆盖掉packet_a的约束 //constraint cstr1 { length inside {[10:20]};}//不同名同时满足...
constraintnot_contains_c {!(2 inside { some_dynamic_array });} 3、约束数组中每个值都是唯一的。 constraintall_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: constraintall_elems_unique_c {foreach(some_dynamic_array[i])foreach(some_dynamic_array...
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。
SystemVerilog 是 Verilog 的扩展，也同样用作为HDL。Verilog 具有reg和wire数据类型，用于描述硬件行为。
)inside{[1:8]};}endclass//使用foreach产生递增的数组元素的值classAscend;randunitd[10];constraint...
SystemVerilog provides the support to use foreach loop inside a constraint so that arrays can be constrained.
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 <...