ems: Design a 4-key digital lock that can be opened only when exactly 2 adjacent keys are pressed. You will use NOR gates. Keypad Ko K₁ K₂ K3 a. Draw a block diagram of the showing electrical data inputs and output of the digital lock. b. Write out the Truth table for the output function. c. Draw a Karnaugh map for the output circling the zeros. d. Determine the essential primes and write these algebraic terms down. e. List the primes that are not essential, but are optional terms in F. f. Find at least one minimum Product of Sums circuit implementing F. g. Identify all the hazards in your circuit. h. Create a Product of Sums expression for F that is hazard free. i. Implement this circuit design using only NOR gates assuming all inputs are available as needed. j. Implement this circuit using only 3 input NOR gates.