queue of 8086 microprocessor is 6 bits
There is no PC register in the 8086/8088. It is called the IP register by Intel and it stands for the Instruction Pointer. It contains the address of the current/next instruction to be executed.
8086 has four multipurpose registers. 1. AX (Accumulator Register) 2. BX (Base Register) 3. CX (Count Register) 4. DX (Data Register) By Aneeta Arshad
stack segment register
i.e.-->mov ax,2000h (in 8086)
Physical address in the 8086/8088 is {Selected Segment Register} * 16 + {Effective Offset Address}. It is a 20-bit address .
What is the need of segments in 8086 micro-processor? Explain how the address of an instruction is calculated in 8086 using segment register
In the 8086 microprocessor, register indirect addressing mode is a method of accessing data in memory using a register to hold the address of the data. In this mode, the effective address of the operand is provided by a register, such as BX, SI, or DI. This allows for flexible data manipulation, as the contents of the register can be easily modified to point to different memory locations. This addressing mode is particularly useful for operations on arrays and data structures.
In the 8086 microprocessor, the register that stores the interrupt and subroutine return address is the Instruction Pointer (IP) register. When an interrupt occurs or a subroutine is called, the current instruction address is pushed onto the stack, allowing the processor to return to that location after the interrupt or subroutine execution is complete. The IP register works in conjunction with the Code Segment (CS) register to determine the effective address of the next instruction to execute.
In the 8086 microprocessor, the DX register has several special uses. It is often paired with the AX register for multiplication and division operations, where DX holds the high-order bits of the result in multiplication and the remainder in division. Additionally, DX is used in I/O operations, particularly for port addresses in conjunction with the IN and OUT instructions. It also serves as a pointer for data in certain string manipulation instructions.
In the 8086, pin 35 (A19/S6) is used as the high order address bit during the beginning of each memory access cycle. Afterwards, it is a spare status pin and is unused.
DI is the Index register in Data segment(16-bit, 64 KB) .Destination Index (DI) is a 16-bit register. DI is used for indexed, based indexed and register indirect addressing, as well as a destination data address in string manipulation instructions.