General Data Registers
Given figure indicate the register organization of 8086. The registers DX, CX, BX and AX are the general purpose 16-bit registers. AX is behaved as 16-bit accumulator, with the lower 8-bits of AX designated as AL and higher 8-bits as AH. AL may be used as an 8-bit accumulator for 8-bit operations. This is the most essential general purpose register having multiple functions.
Figure: Register organisation of 8086
Generally the letters L and H denote the lower and higher bytes of a specific register. For example, CH means the higher 8-bits of the CX register and CL means the lower 8-bits of the CX register. The letter X is referring to specify the all the 16-bit register. The register CX is also refers for default counter in case of loop instructions and string. The register BX is refersfor offset storage for forming physical addresses in case of definite addressing modes. DX register is one of general-purpose register which can be utilized as an implicit destination or operandin case of a few instructions.