Four pushbuttons (B₀, B₁, B₂, and B₃) are used as inputs to a logic circuit. Whenever a button is pushed, it is debounced, after which the circuit loads the button number in binary into a 2-bit register (N). For example, if B₂ is pushed, the register output becomes N = 10₂. The register holds this value until another button is pushed. Use a total of two flip-flops for debouncing. Use a 10-bit counter as a clock divider to provide a slow clock for debouncing. Kd is a signal that is 1 when any button has been pushed and debounced.
(a) Draw a state graph (two states) to generate the signal that loads the register when Kd = 1.
(b) Draw a logic circuit diagram showing the 10-bit counter, the 2-bit register N, and all necessary gates and flip-flops.