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XLAT

Replaces the byte at AL with a byte from a lookup table in memory. The table starts at the address contained in BX. The byte at AL is used as an unsigned index into this table.

The following table covers what the source and destinations can be:

DO NOT support LOCK

XLAT is only supported in 16-bit mode or 32-bit compatibility mode. It is NOT supported in 64-bit mode. Attempting to execute this instruction in 64-bit mode SHALL result in an invalid opcode exception.

The instruction implicitly uses AL as both the index and the destination, and BX as the base address. Because it relies on these specific 8-bit and 16-bit registers, it cannot be used with general-purpose registers of larger sizes (e.g., RAX or RBX) beyond the implicit architectural mapping. Failure to ensure BX contains the correct base address before execution will result in a memory access violation or the retrieval of incorrect data.