MULS - M68K instruction reference

mulsSigned multiply 
Multiplies the value of the first operand by the second operand.
Size .w
Used in Arithmetic, logic and bitsM68K assembly
 
XNZVC –●●00
● set from the result
0 always 0
– not changed
Forms  muls ,   
Operands <ea> An operand using one of the instruction’s supported addressing modes, such as d0, (a0)+ or 4(a1). It may name a register, memory or an immediate value. More
Dn A data register, d0 to d7. More
#imm An immediate value written after #: a number, character or label, such as #10, #$FF or #'a'. It must fit the operation’s size: byte -128 to 255, word -32768 to 65535, or long -2147483648 to 4294967295; signed and unsigned spellings are accepted. More
The result is stored in the second operand. The first operand is read as a word, the second as a long
 move.l #2, d0
muls #-3, d0 ; d0 = -6

move.l #-4, d1
muls #-5, d1 ; d1 = 20

* --- Word operands, long result ---
move.l #$100, d2
muls #$100, d2 ; d2 = $10000