UVM PCM Driver Example.

// Interface Declaration
interface adpcm_int;
 
   logic clk;
   logic frame;
   logic [3:0] data;
 
endinterface: adpcm_int


// Transaction item class adpcm_txn
class adpcm_txn extends uvm_sequence_item;
   `uvm_object_util(adpcm_txn)
 
   rand logic[3:0] data;
   rand int delay;
 
   function new (string name);
      super.new(name);
   endfunction: new
 
   constraint del_bet_pac {delay inside {[1:20]};}
 
endclass: adpcm_txn


// Driver class adpcm_drv
class adpcm_drv extends uvm_driver #(adpcm_txn);
   `uvm_component_utils (adpcm_drv)
 
   adpcm_txn req;
 
   virtual adpcm_int adpcm_if;
 
   function new(string name, uvm_components parent)
      super.new(name, parent);
   endfunction: new
 
   task run_phase (uvm_phase phase);
 
      // Default conditions
      adpcm_if.frame <= 0;
      adpcm_if.data <= 0;
      forever begin
         seq_item_port.get_next_item(req);
         repeat(req.delay) begin
            @(posedge adpcm_if.clk);
         end
 
         adpcm_if.frame <= 1;
         for (int i = 0; i < 8; i++) begin
            @(posedge adpcm_if.clk);
            adpcm_if.data <= req.data[3:0];
            req.data = req.data >> 4;
         end
         adpcm_if.frame <= 0;
         seq_item_port.item_done();
      end
   endtask: run_phase
 
endclass: adpcm_drv

                                                                                                                                                                   
// Sequence Class adpcm_seq
class adpcm_seq extends uvm_sequence #(adpcm_txn);
   `uvm_component_utils (adpcm_seq)
 
   adpcm_txn req;
 
   rand int no_of_reps = 10;
 
   function new (string name);
      super.new(name);
   endfunction: new
 
   task body;
      req = adpcm_txn::type_id::create("req", this);
      for (int i = 0; i < no_of_reps; i++) begin
         start_item(req);
         if (!req.randomize()) begin
            `uvm_error("BODY", "req randomization failed")
         end
         finish_item(req);
         `uvm_info("ADPCM_SEQ BODY", 
            $sformatf("Transmitted frame %0d", i), UVM_LOW)
      end
   endtask: body
 
endclass: adpcm_seq