What is a pointer in a stack?

A stack pointer is a small register that stores the address of the last program request in a stack. When a new data item is entered or “pushed” onto the top of a stack, the stack pointer increments to the next physical memory address, and the new item is copied to that address.

What is a stack pointer Mcq?

A stack pointer is. a 16-bit register in the microprocessor that indicate the beginning of the stack memory. a register that decodes and executes 16-bit arithmetic expression.

Why stack pointer is required?

Stack pointer holds the address of the last accupied memory location of the stack called stack pointer. It is used to save the contents of register if it is required during the execution of a program. It indicates which memory location onward the stack is vacent for further storage.

What is the difference between the stack and stack pointer?

The stack is a LIFO (last in, first out) data structure implemented in the RAM area and is used to store addresses and data when the microprocessor branches to a subroutine. The Stack Pointer register will hold the address of the top location of the stack. …

How many bits is a stack pointer?

16 bits
SP – This is the stack pointer. It is of 16 bits. It points to the topmost item of the stack. If the stack is empty the stack pointer will be (FFFE)H.

Which flag is undefined after shld?

For shifts greater than 1 bit, the OF flag is undefined. If a shift occurs, the AF flag is undefined. If the count operand is 0, the flags are not affected.

Is stack pointer in CPU?

In 8086, the main stack register is called stack pointer – SP. The stack segment register (SS) is usually used to store information about the memory segment that stores the call stack of currently executed program. The CPU then copies the value of AX to the memory word whose physical address is 0x1F81E.

What is PSP and MSP?

Main Stack Pointer (MSP) is the default stack pointer. It is used in the Thread mode when the CONTROL bit[1] (SPSEL) is 0, and it is always used in Handler mode. • Processor Stack Pointer (PSP) is used in Thread mode when the CONTROL bit[1] (SPSEL) is set to 1.

What is the size of stack pointer?

There is a stack pointer and a instruction pointer, the stack pointer having 8 explicit and 8 implicit bits (stack is always in the same 256-byte region) and thus the stack pointer register having 8 bits, the instruction pointer having 16 bits. The 8086, has an 16 bit databus and a 20 bit addressbus.

Which register is the stack pointer?

Stack registers in x86. In 8086, the main stack register is called stack pointer – SP. The stack segment register (SS) is usually used to store information about the memory segment that stores the call stack of currently executed program.

What is the use of stack pointer and program counter?

Stack pointer holds the address of the last program request in a stack while the program counter holds the address of the next instruction that should be executed. While stack pointer tracks the operations of the stack, program counter helps to track the current execution point .

What is the stack pointer inside the CPU?

A stack pointer is a CPU register whose purpose is to keep track of a call stack . In contrast, a program counter is a CPU register that indicates where a computer is in its program sequence. These definitions explain the basic difference between stack pointer and program counter.

What is a stack pointer in 8085?

Register Stack. The register stack is also a memory device present in the memory unit,but it handles only a small amount of data.