Differentiate between program counter and stack pointer, (3 marks)June/July 2020

The program counter (PC) and stack pointer (SP) are both special purpose registers in a computer’s central processing unit (CPU). They are used to store the addresses of instructions and data in memory, and to control the flow of a program.

1. The program counter is a register that stores the address of the next instruction to be executed. It is incremented after each instruction is fetched, so that the CPU can fetch the next instruction in sequence.
2. The stack pointer is a register that stores the address of the top of the stack. The stack is a portion of memory that is used to store data temporarily while a program is running. It is often used to store function arguments, local variables, and other data that is needed only for a short period of time.
3. One key difference between the program counter and stack pointer is that the program counter is used to keep track of the program’s instructions, while the stack pointer is used to keep track of data. The program counter is incremented sequentially, while the stack pointer is updated whenever data is pushed onto or popped off of the stack.