MICROPROCESSOR AND MICROCONTROLLER

Detailed explanation-1: -H and L register pair is used to act as memory pointer and it holds 16 bit address of memory location.

Detailed explanation-2: -(D) H-L pair is an exceptional pair which is used as a memory pointer to locate an address L X H 2000H. H recognize H-L pair of general purpose register. Load 16 bit data immediately in H-L pair it means 2000H is the location of memory where data is stored and it is recall by an instruction MOV A M.

Detailed explanation-3: -The 8085 has seven internal 8-bit registers for data, called A, B, C, D, E, H, and L. Six of these registers can also be used in pairs to hold 16-bit quantities. These pairs are BC, DE and HL, where B, D and H hold the MSB of the value and C, E and L hold the LSB, respectively.

Detailed explanation-4: -Description: The 16-bit contents of the specified register pair are added to the contents of the HL register and the sum is saved in the HL register. The contents of the source register pair are not altered.

Detailed explanation-5: -A register pair should be specified on the A side or the B side, depending on which functional unit an instruction is to be executed on, and whether a cross functional unit data path is utilized by the instruction. You cannot mix A-side and B-side registers in the same register pair operand.