What is address CS IP?

The CS(code segment register) is used to address the code segment of the memory i.e a location in the memory where the code is stored. The IP(Instruction pointer) contains the offset within the code segment of the memory.

What is the use of IP register in 8086?

Instruction Pointer(IP):To access instruction the 8086 uses the register CS and IP. The CS register contains the segment number of the next instruction and IP contains the offset. Unlike other register the IP can’t be directly manipulated by an instruction ,that is,an instruction may nt contain IP as its operands.

What is the address size in 8086?

All internal registers, as well as internal and external data buses, are 16 bits wide, which firmly established the “16-bit microprocessor” identity of the 8086. A 20-bit external address bus provides a 1 MB physical address space (220 = 1,048,576).

What would be the 20-bit physical address of the instruction generated in 8086 after reset?

8086 has 20bit address line. So the maximum value of address that can be addressed by 8086 is 2^20 = 1MB. So 8086 can address the locations ranging between 00000 H to FFFFF H.

How does 8086 compute physical address?

I learnt that the physical address is calculated by shifting the segment address (16-bit) left 4 times and adding it with the 16-bit offset address. The memory in the 8086 architecture is 1M.

How many address lines are there in 8086 microprocessor?

The number of address lines in 8086 is 20, 8086 BIU will send 20bit address, so as to access one of the 1MB memory locations. The four segment registers actually contain the upper 16 bits of the starting addresses of the four memory segments of 64 KB each with which the 8086 is working at that instant of time.

What is the reset procedure of 8086?

RESET procedure of 8086. The reset pin of 8086 and other processors will cause the CS:IP to point to FFFF:0000 which is the lowest 16bytes of the memory. In that location there is a jump instruction to somewhere else in the memory space to initialize the processor.

What happens when an interrupt occurs in 8086 microprocessor?

In 8086 microprocessor following tasks are performed when microprocessor encounters an interrupt: The value of flag register is pushed into the stack. It means that first the value of SP (Stack Pointer) is decremented by 2 then the value of flag register is pushed to the memory address of stack segment.

What is stack segment in 8086 microprocessor?

The stack segment is that segment of memory which is used to store stack data. The number of address lines in 8086 is 20, 8086 BIU will send 20bit address, so as to access one of the 1MB memory locations.