* 8086 microprocessor includes: * Fourteen 16-bit registers. * Four data registers, AX, BX, CX, DX * The status register, SR, with nine of its bits implemented for status and control flags. * The instruction pointer, IP * Two pointer registers, BP, SP ?? * Two index registers, SI, DI ?? * Four segment registers, CS, DS, SS, ES * The memory address space is 1 Mbytes and the I/O address space is 64 Kbytes in length.
* Register Organization of 8086 microprocessor: a) General Purpose Registers i) The 8086 has 4 16-bit general purpose registers labelled AX, BX, CX & DX. Each 16-bit general purpose register can be split into two 8-bit registers. The letters L & H specify the lower & higher bytes of a particular register. The letter X is used to specify the complete 16-bit register. ii) General purpose registers are either used for holding data, variables & intermediate results temporarily. They can also be used as counters or for storing offset address. iii) Refer Fig. 2(a).
b) Segment Registers iv) The 1Mb of memory is dividen into segments, with a max size of segment as 64Kb. 8086 allows only four