construct a block diagram and an ASMD chart for a digital systemthat counts the number of people in a room. The one door through which people enter the room has a photocell that changers asignal x from 1 to 0 when the light interrupted. they leavethe room from a second door with a similar photocell that changes asignal y from 1 to 0 when the light is interrupted. the data path circuit consists of up-down counter with a display that shows how many people are in the room.