Registers:
Most of the registers contain data/instruction offsets within 64 KB memory segment. There are four different 64 KB segments for instructions, stack, data and extra data. To specify where in 1 MB of processor memory these 4 segments are located the 8086 microprocessor uses four segment registers:
Code segment
(CS) is a 16-bit register containing address of 64 KB segment with
processor instructions. The processor uses CS segment for all accesses
to instructions referenced by instruction pointer (IP) register. CS
register cannot be changed directly. The CS register is automatically
updated during far jump, far call and far return instructions.
REGISTER SET OF 8086 MICROPROCESSOR