AX is the 16 lower bits of EAX. AH is the 8 high bits of AX (i.e. the bits 8-15 of EAX) and AL is the least significant byte (bits 0-7) of EAX as well as AX. Example (Hexadecimal digits): EAX: 12 34 56 78 AX: 56 78 AH: 56 AL: 78

AX is the primary accumulator; it is used in input/output and most arithmetic instructions. For example, in multiplication operation, one operand is stored in EAX or AX or AL register according to the size of the operand. BX is known as the base …

Aug 12, 2024 · There are 8 general-purpose registers in the 8086 microprocessor. 1. AX: This is the accumulator. It is of 16 bits and is divided into two 8-bit registers AH and AL to also perform 8-bit instructions.

Mar 20, 2020 · AX was a 16-bit accumulator, while AH and AL could be thought of as 8-bit registers on their own or as a way to access the high-order and the low-order bytes of AX. The X in AX meant to be a placeholder that stood for both H and L .

The AX, AH, and AL sub-registers are all accessible within EAX: Fig 3 : The 32-bit EAX register retained AX, AH, and AL as sub-registers. The sub-register AX allows us to access the lower 16 bits of EAX.

The least significant byte of AX can be used as a single 8-bit register called AL, while the most significant byte of AX can be used as a single 8-bit register called AH. These names refer to the same physical register.

ax is the 16-bit, "short" size register. It was added in 1979 with the 8086 CPU, but is used in DOS or BIOS code to this day. al and ah are the 8-bit, "char" size registers. al is the low 8 bits, ah is the high 8 bits. They're pretty similar to the old 8-bit registers of the 8008 back in 1972.

May 15, 2016 · I'm having trouble understanding registers in x86 Assembly, I know that EAX is the full 32 bits, AX is the lower 16 bits, and then AH and AL the higher and lower 8 bits of AX, But I'm doing a question. If AL=10 and AH=10 what is the value in AX?

Oct 26, 2018 · There are special short-form encodings of many instructions using AL/AX/EAX (like add al, 2 is 2 bytes, but add cl, 2 is 3 bytes). 8086 (and later extensions in 186/386) made the registers more orthogonal than 8080 so you can add dx, cx without having to use the accumulator for all ALU instructions.

AH AL AX = AH | AL BH BL BX = BH | BL CH CL CX = CH | CL DH DL DX = DH | DL BP SI DI SP General Purpose Registers: 8,16,32 bits 31 15 7 0 EAX EBX ECX EDX EBP ESI EDI ESP CS DS SS ES FS GS Segment Registers: 16 bits (hold 16-bit segment selectors to identify memory segment) Instruction Pointer (EIP): 32 bits