Interested to Buy Any Domain ? << Click Here >> for more details...
Answer Posted / amita
The program counter, or PC (also called the instruction pointer[1], or instruction address register[2], or just part of the instruction sequencer[3] in some computers) is a processor register that indicates where the computer is in its instruction sequence. Depending on the details of the particular computer, the PC holds either the address of the instruction being executed, or the address of the next instruction to be executed.
In most processors, the instruction pointer is incremented automatically after fetching a program instruction, so that instructions are normally retrieved sequentially from memory, with certain instructions, such as branches, jumps and subroutine calls and returns, interrupting the sequence by placing a new value in the program counter.
Such jump instructions allow a new address to be chosen as the start of the next part of the flow of instructions from the memory. They allow new values to be loaded (written) into the program counter register. A subroutine call is achieved simply by reading the old contents of the program counter, before they are overwritten by a new value, and saving them somewhere in memory or in another register. A subroutine return is then achieved by writing the saved value back in to the program counter again.
| Is This Answer Correct ? | 29 Yes | 22 No |
Post New Answer View All Answers
What does the parity flag do?
What are the functions of general purpose registers?
What are the two major differences between intr and other interrupts (hardware)?
The operation being performed by the 8085 can be checked by which pins?
How is the system clock calculated in the 8085?
What is the difference between 8085 microprocessor and a 8086 microprocessor?
List the various registers of 8085?
What are the boons and banes of having more general purpose registers in a microprocessor.
How many bits microprocessor was first developed?
What is coprocessor?
Mention interrupts pins of 8085?
What is base segment address?
What number of the times the instruction sequence below will loop before coming out of loop is MOV AL, 00hA1: INC AL JNZ A1
What is tri-state logic?
Define the process of an interrupt operation in the 8086?
