Siemens C500 User Manual page 83

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 (0FF H ) the overflow flag is
set; otherwise it is cleared. The carry flag is always cleared.
Example: Originally the accumulator holds the value 80 (50 H ). Register B holds the value 160
(0A0 H ). The instruction
MUL
will give the product 12,800 (3200 H ), so B is changed to 32 H (00110010 B ) and the
accumulator is cleared. The overflow flag is set, carry is cleared.
Operation: MUL
(A7-0)
(B15-8)
Encoding: 1 0 1 0
Bytes: 1
Cycles: 4
Semiconductor Group
AB
¬ (A) x (B)
0 1 0 0
4-57
Instruction Set
C500 Family
1998-04-01