8051 Instruction Set Manual

MUL

The MUL instruction multiplies the unsigned 8-bit integer in the accumulator and the unsigned 8-bit integer in the B register producing a 16-bit product. The low-order byte of the product is returned in the accumulator. The high-order byte of the product is returned in the B register. The OV flag is set if the product is greater than 255 (0FFh), otherwise it is cleared. The carry flag is always cleared.

See Also: DIV

MUL AB
BA = A * B

MUL AB