Process of automatic chocolate wending machine...

(1) <font color=#AA0000>When a child inserts co</font>in into the coin slot machine to buy a chocolate, the “ first coin into the machine “ generates a trigger pulse. This trigger pulse serves as a start signal for the coin slot machine’s built-in timer. This timer is designed for a 2 minute count-down, using hardware ( this 2 minute time is fixed through hardware ) . Timer’s countdown starts upon receiving the signal (trigger pulse ). The child is expected to insert balance amount within two minutes , to get his chocolate.
(2) The coin slot machine has three dedicated 8-bit registers ( R1, R2, R5 ) for denominations of Rs. 1, Rs. 2 and Rs. 5 respectively. These registers store the information bout the number of coins inserted. When the child inserts a coin – for example , a Five rupee coin, then the R5 register’s D0 bit is set to 1. If the child inserts a second 5 Rupee coin, then the D1 bit of the same register ( R5 ) is set to 1, indicating that the child has inserted 2 coins of 5 rupee denomination. As a result, the content of R5 is 0000 0011. The inserted coins are routed to a coin box for the collection by the owner of ACVM. Thus the insertion of coins in the coin-slot-machine generates data in the three registers.
(3) Within two minutes if the child inserts the balance amount ( cost of the chocolate) , the following tasks are performed :