(a) Interrupt-driven I/O, though more efficient than simple programmed I/O, still requires the active intervention of the processor to transfer data between memory and an I/O module, and any data transfer must traverse a path through the processor. Thus, both these forms of I/O suffer from two inherent drawbacks. Briefly describe the two drawbacks. [4 Marks] (b) (i) What is a data hazard? Name and describe a hardware technique that overcomes most data hazards. [4 Marks] (ii) Identify any four types of register data dependencies in the following piece of code. L1: MUL r2, r3, r4 L2: ADD r3, r2, r4 L3: ADD r4, r2, r4 L4: SUB r3, r4, r3 [4 Marks] (c) When a multiple device interrupts have occurred; how does the processor decide which one to process? [8 Marks] (d) When DMA module takes control of a bus, and while it remains control of the bus, what does the processor do? [3 Marks] (e) What, if any, is the difference between a multicore processor and a coprocessor? [2 Marks]