What is Multiply Accumulate Unit (MAC) in ARM? All Questions › Category: Embedded System › What is Multiply Accumulate Unit (MAC) in ARM? 0 Vote Up Vote Down Chetan Shidling Staff asked 5 years ago I need short information. 1 Answers 0 Vote Up Vote Down Chetan Shidling Staff answered 5 years ago The MAC helps integer and long integer multiplication. The integer multiplication instructions carry the multiplication of two 32-bit registers and place the result in a third 32-bit register.