When pop instruction is executed?

When pop instruction is executed?

When pop instruction is executed the stack pointer is incremented by? When POP H instruction is executed, two data bytes from the HL registers that were previously stored on the stack are transferred back to the HL pair. After executing this instruction stack pointer is incremented by two.

What is the operation of pop instruction? Home » Instructions » POP. The POP instruction reads a byte from the address indirectly referenced by the SP register. The value read is stored at the specified address and the stack pointer is decremented. No flags are affected by this instruction.

Can be changed directly using pop instruction? SS register can be changed directly using POP instruction. Data segment (DS) is a 16-bit register containing address of 64KB segment with program data. By default, the processor assumes that all data referenced by general registers (AX, BX, CX, DX) and index register (SI, DI) is located in the data segment.

When pop instruction is executed? – Related Questions

How many bytes are copied by pop instruction?

pop has the same choices of size: 16, 32, or 64, except no 32-bit pop in 64-bit mode. In NASM source code, push 123 assembles to the operand-size that matches the mode you’re in.

When a call instruction is executed the stack pointer register is?

The register used to access the stack is called the stack pointer (SP) register. In I/O memory space, there are 2 registers named SPL (the low byte of SP) and SPH (the high byte of. SP). The SP is implemented by these 2 registers. In AVRs with more than 256 bytes of memory have two 8-bit registers.

When the call instruction is executed the top most element of stack comes out to be?

topmost element of the stack is the address of the instruction next to the call instruction so that when RET is executed then PC is filled with that address and so the pointer moves to the main program and continue with its routine task.

In which instruction after each execution of the instruction the stack pointer is decremented by 2?

So, the push operation decrements SP by 2 and then stores the two bytes contents of the operand onto the stack. Explanation: Since PUSH operation transfers data to stack from a register or memory location.

When Cmpsb Cmpsw instruction is executed which of the following flags gets affected?

Which of the following flags gets affected when a compare instruction, i.e. CMPSB, CMPSW or CMPSD is executed? Explanation: Whenever a compare instruction over strings is executed, the status flags are affected. From the mentioned options, only Zero Flag is a status flag.

What is the content of stack pointer?

The stack pointer “SP” is the register which holds the address of the top of the stack. On the HC12 and HCS12, the SP points to the last byte placed on the stack. That is, the SP register contains the memory address of the last byte put on the stack, and data is pushed or pulled to/from this address.

What is the instructions which after execution transfer control to the next instruction in the sequence are called?

The instructions which after execution transfer control to the next instruction in the sequence are called. Sequential control flow instructions.

What does Pop do in assembly?

The pop instruction removes the 4-byte data element from the top of the hardware-supported stack into the specified operand (i.e. register or memory location). It first moves the 4 bytes located at memory location [SP] into the specified register or memory location, and then increments SP by 4.

What is push and pop instructions?

Instructions that store and retrieve an item on a stack. Push enters an item on the stack, and pop retrieves an item, moving the rest of the items in the stack up one level.

How the push and pop instructions are executed?

PUSH and POP. In case of PUSH operation, the SP register gets decreased by 2 and new data item used to insert on to the top of the stack. On the other hand, in case of POP operation, the data item will have to be deleted from the top of the stack and the SP register will get increased by the value of 2.

What register can be changed directly using pop instruction in 8086?

SS register can be changed directly using POP instruction. Data segment (DS) is a 16-bit register containing address of 64KB segment with program data. By default, the processor assumes that all data referenced by general registers (AX, BX, CX, DX) and index register (SI, DI) is located in the data segment.

What are registers used for?

Registers are small amounts of high-speed memory contained within the CPU. They are used by the processor to store small amounts of data that are needed during processing, such as: the address of the next instruction to be executed.

How many bytes are x86 instructions?

x86 instructions can be anywhere between 1 and 15 bytes long. The length is defined separately for each instruction, depending on the available modes of operation of the instruction, the number of required operands and more.

How many bytes are stored on the stack by a push ax?

To pop a value from the stack, the POP instruction is used. These first instruction shall push the value stored in AX (16-bit register) to the stack. This is done by subtracting a value of 2 (2 bytes) from SP.

How many bytes are used in the stack frame?

The stack frame is 32-byte-aligned.

How stack is used in call instructions?

Functions of the call stack. As noted above, the primary purpose of a call stack is to store the return addresses. When a subroutine is called, the location (address) of the instruction at which the calling routine can later resume needs to be saved somewhere.

What is the role of stack during a call instruction?

Stack is used to store and retrieve return addresses during function calls. It is also used to transfer arguments to a function. On a microprocessor it is also used to store the status register contents before a context switch.

What is the stack pointer used for?

A stack pointer is a small register that stores the address of the last program request in a stack. A stack is a specialized buffer which stores data from the top down. As new requests come in, they “push down” the older ones.

Which addressing mode is used in pushing or popping any element on or from the stack?

Which addressing mode is used in pushing or popping any element on or from the stack? Explanation: If we want to push or pop any element on or from the stack then direct addressing mode has to be used in it, as the other way is not accepted.

When pop instruction is executed the stack pointer is decremented by two?

In POP instruction, after each execution of the instruction, the stack pointer is a) incremented by 1 b) decremented by 1 c) incremented by 2 d) decremented by 2 Answer: c Explanation: The actual current stack top is poped into the specific operand as the contents of stack top memory is stored in AL&SP and further

Which addressing mode is being used in the given instruction mov ax 1234H *?

The instruction, MOV AX, 1234H is an example of. register addressing mode.