Subversion Repositories oms8051mini

//+++++++++++++++++++++++++++++++++++++++++++++++++

//   DUT With assertions

//+++++++++++++++++++++++++++++++++++++++++++++++++

module concurrent_assertion(

  input wire clk,req,reset,

  input wire gnt);

//=================================================

// Sequence Layer

//=================================================

sequence req_gnt_seq;

  // (~req & gnt) and (~req & ~gnt) is Boolean Layer

 (req & ~gnt) ##1 (~req & gnt) ##1 (~req & ~gnt) ;

endsequence

//=================================================

// Property Specification Layer

//=================================================

property req_gnt_prop;

  @ (posedge clk)

    disable iff (reset)

      req |-> req_gnt_seq;

endproperty

//=================================================

// Assertion Directive Layer

//=================================================

req_gnt_assert : assert property (req_gnt_prop)

                 else

                 $display("@%0dns Assertion Failed", $time);

endmodule

//+++++++++++++++++++++++++++++++++++++++++++++++

//   Testbench Code

//+++++++++++++++++++++++++++++++++++++++++++++++

module concurrent_assertion_tb();

reg clk = 0;

reg reset, req = 0;

reg gnt;

always #3 clk ++;

initial begin

  reset <= 1;

  #20 reset <= 0;

  repeat (100) @ (posedge clk);

  // Make the assertion pass

  @ (posedge clk) #1 req  <= 1;

  @ (posedge clk) #1 req <= 0;

  repeat (100) @ (posedge clk);

  // Make the assertion fail

  @ (posedge clk) #1 req  <= 1;

  repeat (5) @ (posedge clk);

  @ (posedge clk) #1 req <= 0;

  req <= 0;

  repeat (100) @ (posedge clk);

  #10 $finish;

end

//=================================================

// Actual DUT RTL

//=================================================

always @ (posedge clk)

  gnt <= #1 req ;

concurrent_assertion dut (clk,req,reset,gnt);

// Dumping Waveforms

initial begin //{

    $shm_open("simvision.shm");

    $shm_probe("AC");

end //}

endmodule