7. Which of the following modifications to the sequential logic circuit (SLC) block diagram would most likely lead to non-sequential behavior?

  1. INPUT lines are disconnected, but the CLOCK line is not affected.
  2. The INPUT LOGIC BLOCK is removed so that the MEMORY ELEMENTS inputs and outputs are interfaced directly.
  3. The OUTPUT LOGIC BLOCK is removed so that the MEMORY ELEMENTS outputs are directly connected to the SLC OUTPUTLINES.
  4. The feedback path between the MEMORY ELEMENTS and the INPUT LOGIC BLOCK is opened.
  5. No modification stated above would lead to nonsequential behavior.

4 is CORRECT. When the feedback path is severed, no information concerning the present state is fed back to determine the next state; therefore, the next state is determined strictly by the inputs--simple combinational logic can do this.

[ Go Back To Question 7 ]

[ Go Back To The Beginning Of Quiz ]