Inside constraint

UVM
1

Hi,

 req.randomize() with {if(cfg.addr == 7)
                                addr  inside {cfg.valid_slave_address}; 
                                if (index == 0 && command == (3'b011 || 3'b001)) 
                                data[1] == command;};

even though when I passing the command == 3’b011 & 3’b001 its not taking the command value instead of its taking some random value can any one help me how to rewrite that one.

thanks

2

In reply to lalithjithan:

Answering by inferring that the question is that :

You are getting data[1] not equal to command even when you are passing command as one of the following value :
3’b011
3’b001

The issue is with the way you have written the condition :

 req.randomize() with {if(cfg.addr == 7)
                                addr  inside {cfg.valid_slave_address}; 
                                if (index == 0 && command == (3'b011 || 3'b001))  // <--
                                data[1] == command;};

The code check -

command == ( 3’b011 || 3’b001 )
which is equivalent to -
command == (true logical_OR true )
command == 1

you should write it as following to get data[1] = command when command is either 3 or 1 :

 req.randomize() with {if(cfg.addr == 7)
                                addr  inside {cfg.valid_slave_address}; 
                                if (index == 0 && (command == 3'b011 || command == 3'b001)) // <-- 
                                data[1] == command;};

Hope it helps.

3

In reply to @nurag:

You could also use the inside operator for this:

 req.randomize() with {if(cfg.addr == 7)
                                addr  inside {cfg.valid_slave_address}; 
                                if (index == 0 && command inside {3'b011, 3'b001}) // <-- 
                                data[1] == command;};