SV Day 24 — UVM Config Database

Config Database (No Hardcodes)

Pass configuration without hardcoding parameters:

// In test, before build
uvm_config_db #(int)::set(null, "env.drv", "delay", 5);
uvm_config_db #(string)::set(null, "env", "mode", "stress");

// In component, read during build_phase
class my_driver extends uvm_driver;
  int delay;
  function void build_phase(uvm_phase phase);
    super.build_phase(phase);
    if(!uvm_config_db #(int)::get(this, "", "delay", delay)) begin
      delay = 0;  // default
    end
  endfunction
endclass

Testbench with Config

class my_test extends uvm_test;
  virtual function void build_phase(uvm_phase phase);
    super.build_phase(phase);

    // Configure agent for different scenarios
    uvm_config_db #(int)::set(this, "env.agt*", "mode", STRESS);
    uvm_config_db #(int)::set(this, "env.agt*", "num_txns", 10000);

    // Hierarchical config: can override per-agent
    uvm_config_db #(int)::set(this, "env.agt0", "mode", SANITY);
    uvm_config_db #(int)::set(this, "env.agt1", "mode", STRESS);
  endfunction
endclass

Key Takeaways

✅ No hardcoded parameters
✅ Reuse testbenches for multiple scenarios
✅ Hierarchical config paths

Day 25: Complete UVM testbench wrap-up and methodology review.