Write down the next-state and output-function tables for the traffic light controller described in Exercise B.41.

Exercise B.41

We wish to add a yellow light to our traffic light example on page B-68. We will do this by changing the clock to run at 0.25 Hz (a 4-second clock cycle time), which is the duration of a yellow light. To prevent the green and red lights from cycling too fast, we add a 30-second timer. Th e timer has a single input, called TimerReset, which restart the timer, and a single output, called TimerSignal, which indicates that the 30-second period has expired. Also, we must redefine the traffic signals to include yellow. We do this by defining two out put signals for each light: green and yellow. If the output NSgreen is asserted, the green light is on; if the output NSyellow is asserted, the yellow light is on. If both signals are off, the red light is on. Do not assert both the green and yellow signals at the same time, since American drivers will certainly be confused, even if European drivers understand what this means! Draw the graphical representation for the finite-state machine for this improved controller. Choose names for the states that are different from the names of the outputs.