You will be building (and then, later, extending) an FSM to drive your Y86. A 6-

Question

You will be building (and then, later, extending) an FSM to drive your Y86. A 6-bit field should more than enough space to specify the current state. In the FSM we will build up, most of the time, each state has exactly one "next" state. However, there are also exceptions: Sometimes, we want to self-loop if DMemReady is not set Sometimes, we want to self-loop if IMemReady is not set, but then to branch to one of about 12 states, based on the icode field. So... we need microsequencer (as we built in the traffic light FSM) to help us calculate next-state transitions like this. Build this microsequencer for your Y86: Don't use any internal registers; the outputs should follow directly from whatever the inputs are.

Explanation / Answer

Up to now, every circuit that was presented was a combinatorial circuit. That means that its output is dependent only by its current inputs. Previous inputs for that type of circuits have no effect on the output.

However, there are many applications where there is a need for our circuits to have “memory”; to remember previous inputs and calculate their outputs according to them. A circuit whose output depends not only on the present input but also on the history of the input is called a sequential circuit.

In this section we will learn how to design and build such sequential circuits. In order to see how this procedure works, we will use an example, on which we will study our topic.

So let’s suppose we have a digital quiz game that works on a clock and reads an input from a manual button. However, we want the switch to transmit only one HIGH pulse to the circuit. If we hook the button directly on the game circuit it will transmit HIGH for as few clock cycles as our finger can achieve. On a common clock frequency our finger can never be fast enough.

The desing procedure has specific steps that must be followed in order to get the work done

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.