What is Type Safety in UVM?

Type safety refers to enforcing correct data types during coding so that a variable of one type cannot be mistakenly used as another incompatible type.

In the context of UVM and SystemVerilog, this means that:
The compiler ensures the data being passed or retrieved is of the expected type, reducing the chance of runtime errors.

Why is type safety important?

• Prevents Bugs: Mistakes such as treating an integer as a string or a configuration object as a bit would be caught at compile time.
• Easier Debugging: Type mismatches are flagged early, not during simulation when it’s harder to trace.
• Code Clarity: Makes interfaces between components more explicit and self-documenting.

Example in UVM

With uvm_config_db (Type-Safe)

uvm_config_db#(int)::set(this, "*", "timeout", 100);
int my_timeout;
uvm_config_db#(int)::get(this, "", "timeout", my_timeout); // ✅ Type-safe

//If you try to get() it as a string, the simulator will report a type mismatch at compile time.

uvm_config_db#(string)::get(this, "", "timeout", my_timeout); //ERROR during simulation time

With uvm_resource_db (Less Strict):

uvm_resource_db#(int)::set("TIMEOUT", 100, this);
string timeout_str;
uvm_resource_db#(string)::read_by_name("TIMEOUT", timeout_str); // ⚠️ May lead to undefined behavior

This will compile, but could cause unpredictable runtime behavior.

Summary