Q1. Give a block diagram of the PLC system which comprises the following:

a) CPU
b) System clock
c) Power supply
d) Input and output interfaces
e) Keyboard
f) Display device
g) Necessary types of memory.

Describe in brief the function and necessary features of each and every block.

Q2. Use the diagram shown below to briefly describe the fetch/execute cycle of a microprocessor for the instruction 32 00 BC.

The instruction is stored in memory locations 1661 to 1663. The op code signifies store the contents of the accumulator in the memory address location. The address given is in the reverse order. The content of the accumulator are 78H. Point out the contents of PC, AS, registers, accumulator and address BC00 after the cycle is done.