The previous problem highlights a good method for creating an arbitrary waveform using an initial procedure with (#) delays as needed. But often we want to test all input combinations, for example as they would appear in a standard truth table, like the one shown here for inputs a, b, c. Notice, the Verilog code below would generate a clock signal (clk) with a period of 20ns (assuming the default timescale of 1ns) by inverting clk every 10ns. parameter TU = 10; initial clk = 0; always #TU clk = ~olk; 001 010 011 100 101 110 1 Using the code above as an example, write a code block that will create the periodic waveforms for signals a,b,c from the truth table, where the period of c is 100ns, b is 200ns, and a is 400ns. Also, make the period of each signal is based on a single time variable, like TU in the example above. Your code block should also show the procedure necessary to start the signals at 0,0,0. You may find this handy in ongoing and future work with Verilog.