System verilog constraint

SystemVerilog
,
1

I get all the ranges to be 0 in the following constraint code.


int start_addr = 'h0;
  int end_addr	 = 'hFF;
  
  rand int range[];
  
  rand int num_partition;
  
  rand int partition_size[];
  
  constraint c1{
    num_partition inside {[1:10]};
    range.size() == num_partition;
    partition_size.size() == num_partition; 
    foreach(partition_size[i]){
      partition_size[i] inside {[1:200]};
      partition_size[i+1] > partition_size[i];
    }
  }
  
  constraint c2{
        unique{partition_size};
      }
  constraint c3{
    foreach (range[i]){
      if(i==0) 
        range[i] == start_addr;
      else {
        range[i] == range[i-1] + partition_size[i-1];
      }
    }
  }

Output:


num_partition           6 

range =          0 partition_size          21
range =          0 partition_size          72
range =          0 partition_size          78
range =          0 partition_size          80
range =          0 partition_size          81
range =          0 partition_size          84
2

Its because of the constraint which you mentioned above it is causing randomize to fail and you see all range value to be zero. Try this below one


constraint c1{
    num_partition inside {[1:10]};
    range.size() == num_partition;
    partition_size.size() == num_partition; 
    foreach(partition_size[i]){ 
      partition_size[i] inside {[1:200]};
      if (i < num_partition-1)      
  partition_size[i+1] > partition_size[i];
    }
  }
3 

  int start_addr = 'h0;
  int end_addr	 = 'hFF;
 
  rand int range[];
 
  rand int num_partition;
 
  rand int partition_size[];
 
  constraint c1{ num_partition inside {[1:10]};
                 range.size() == num_partition;
                partition_size.size() == num_partition; }
    
   constraint c2{ foreach(partition_size[i])
   				 {partition_size[i] inside {[1:200]};}
                 }
      
   constraint C3{ foreach(partition_size[i])
        		if(i<partition_size.size-1)
      		    {partition_size[i+1] > partition_size[i];}
                 }
 
   constraint c4{unique{partition_size};}
   
   constraint c5{foreach (range[i])
                    {
                    if(i==0) 
        		range[i] == start_addr;
      		    else 
                       {range[i] == range[i-1] + partition_size[i-1];}
    		    }
  		}

Regards,
Shanthi

4

Thank you! found the bug