How to write a constraint to randomize any 5 bits out of a 32 bit variable

SystemVerilog
,
2

In reply to surya narayana Gutha:
my solution


// constraint to randomize any 5 bits out of a 32 bit variable? 
// select 5 bits to randomize
class C; 
	bit[31:0] v; 
	rand bit[4:0] b; 
	rand bit[31:0] pick5;   
	constraint ct5 {$countones(pick5)==5;}
	
	function void post_randomize();
	   automatic int j=0; 
	   for(int i=0; i<=31; i=i+1) begin :for1
	    	if(pick5[i]) begin 
	   	    	 v[i]=b[j]; 
	   	    	 j=j+1'b1; 
	   	    end 
	   	    else v[i]=0;
	   end : for1
	endfunction : post_randomize
endclass
// 
import uvm_pkg::*; `include "uvm_macros.svh" 
module top; 
	timeunit 1ns;     timeprecision 100ps;   
	C c; 
	initial begin 
		c=new(); 
		repeat(10) begin   
			if (!randomize(c)) `uvm_error("MYERR", "This is a randomize error")
			$display("pick5= %b, b=%b, v=%b", c.pick5, c.b, c.v); 
		end 
		$stop; 
	end 
endmodule  
pick5= 00000110100000010000000000001000, b=00101, v=00000000100000000000000000001000
# pick5= 00000000001000000100100100100000, b=00011, v=00000000000000000000000100100000
# pick5= 00001001100000000000100000000010, b=10110, v=00001000100000000000100000000000
# pick5= 00000000010000010000000110000100, b=00000, v=00000000000000000000000000000000
# pick5= 00000000100000010100011000000000, b=00101, v=00000000000000000100001000000000
# pick5= 00010000000000010000001001000010, b=10000, v=00010000000000000000000000000000
# pick5= 01000000000000100010100000000100, b=00111, v=00000000000000000010100000000100
# pick5= 00110000010000000000101000000000, b=01100, v=00010000010000000000000000000000
# pick5= 10000000000010101000010000000000, b=11111, v=10000000000010101000010000000000
# pick5= 00101000010000100010000000000000, b=00000, v=00000000000000000000000000000000

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