SAB80515 Datasheet, PDF (184/270 Pages) Siemens Semiconductor Group – 8-Bit Single-Chip Microcontroller Family

Instruction Set
MUL
AB
Function:
Multiply
Description:
MUL AB multiplies the unsigned eight-bit integers in the accumulator and register
B. The low-order byte of the sixteen-bit product is left in the accumulator, and the
high-order byte in B. If the product is greater than 255 (0FFH) the overflow flag is
set; otherwise it is cleared. The carry flag is always cleared.
Example:
Originally the accumulator holds the value 80 (50H). Register B holds the value 160
(0A0H). The instruction
MUL AB
will give the product 12,800 (3200H), so B is changed to 32H (00110010B) and the
accumulator is cleared. The overflow flag is set, carry is cleared.
Operation: MUL
(A7-0)
(B15-8) ^{← (A) x (B)}
Encoding:
Bytes:
Cycles:
1010 0100
1
4
Semiconductor Group
184