Select an instruction to view timings

Data from 8088 to Pentium

MOV

Move data

Example: mov eax, ebx

Cycle Timings

Operands	Bytes	8088	V20	186	286	386	486	Pentium	Pair

Legend

reg: General register

mem: Memory address

imm: Immediate data

acc: Accumulator (AL/AX/EAX)

NP: Not Pairable

UV: Pairable in U or V pipe

PU/PV: Pairable in U/V only

d(n): Displacement bytes

i(n): Immediate bytes

+EA: Add Effective Address calc time (5-12 cycles on 8088)

+m: Add bytes of next instruction (prefetch reload)

*: Pairable with penalties/restrictions

Timing Notes

i (Immediate): Represents the size in bytes of the immediate data (constants) in the instruction. For example, `ADD AX, 1234h` has a 2-byte immediate (16-bit), while `ADD AL, 12h` has a 1-byte immediate.

d (Displacement): Represents the offset or memory address displacement bytes. A short jump has a 1-byte displacement, while a memory operand like `[BX+100h]` has a 2-byte displacement.

Division (DIV/IDIV): Cycle counts for division vary significantly because the CPU performs an iterative calculation (like doing long division by bit-shifting). The total time depends on the number of significant bits in the operands. Smaller numbers divide faster.