An accumulator register is 32bit long and is part of the arithmetic and logic unit of the central processing unit. It holds the operands and the results generated by the arithmetic operations. The second one is status register. It is a 16-bit long register. Each bit of this register is a flag or status indicator about the execution of an arithmetic operation. The respective bits of this register indicate whether there has been any overflow, underflow a carry has been generated or the result has been zero or negative and similar other information. The third one is the stack pointer.
A stack is a set array of memory locations usually in the main memory in which data items are stored in some order. Operation of the stack in analogous to a stack of books where you can add another book by putting it on top. A book may also be removed from the top of the stack only. In a computer the stack is used to store certain data values which may be retrieved in a given order. This order is described as last in first our method. A data value is always added to the top of the stack. This is a PUSH operation while removing a value from the top is called POP operation.
A stack is a set array of memory locations usually in the main memory in which data items are stored in some order. Operation of the stack in analogous to a stack of books where you can add another book by putting it on top. A book may also be removed from the top of the stack only. In a computer the stack is used to store certain data values which may be retrieved in a given order. This order is described as last in first our method. A data value is always added to the top of the stack. This is a PUSH operation while removing a value from the top is called POP operation.