Simulating a Verilog Description module bigtest;. calc1_top D1(out_data1, out_data2, out_data3, out_data4, out_resp1, out_resp2, out_resp3, out_resp4, scan_out, a_clk, b_clk, c_clk, error_found, req1_cmd_in, req1_data_in, req2_cmd_in, req2_data_in, req3_cmd_in, req3_data_in, req4_cmd_in, req4_data_in, reset, scan_in); Go to the directory with the Verilog code I assume that it is all in one directory Compile and simulate the top file, testbench.v This will force the compilation/simulation of all other files testbench.v

Running VCS Type vcs -RI testbench.v The Interactive Window appears All other windows invoked from here “Window” pulldown on top bar window icons below top bar

Waveform Window Open the Waveform Window Need to select the signals you want to see, use Hierarchy Window

Hierarchy Window Select the bigtest module to see its signals Drag-and-drop the signals into the Waveform Window

Waveform Window with Signals The signals are on display, but they are blank

Execute Simulation Simulate by selecting Continue Printed results are shown in top pane

Waveforms Results Waveform Window is updated with results Zoom out and scroll over time

Waveforms Results, Zoomed and Scrolled

Testbench for Combinational Logic module stimulus; reg clk; reg [7:0] in1,in2; wire[7:0] out; // instantiate the design block adder r1(out, in1, in2); initial begin in1 = 8b’ ; in2 = 8b’ l; #10 in1 = 8b’ ; in2 = 8b’ ; end endmodule Apply test data to all inputs Add a delay, then check results and apply new inputs

Testbench for Sequential Logic module stimulus; reg clk; reg reset; wire[3:0] q; // instantiate the design block ripple_carry_counter r1(q, clk, reset); // Control the clock initial clk = 1'b0; always #5 clk = ~clk; // Control the reset initial begin reset = 1'b1; #10 reset = 1'b0; #20 reset = 1'b1; #10 reset = 1'b0; #20 $stop; end endmodule Change inputs before positive clock edge Check results after positive clock edge