I have some question almost uncorrelated, so I'll enureamted it, hope you can help me:
1) I'm studing RTL Design, and the question is at level of data path, arithmetic unit ecc. I don't understand why and how a shifter can be used to do the multiplication and division operation. For example, if someone ask me "how many adder (or shifter) is needed to do a multiplication between to operand composed by X bit", what is the method that I have to apply to answer this question? Another question. In a book I've read that the operation A+B=K, in wich the output is 1 if the sum of A and B is egual to K, 0 otherwise, can be performed evaluting the Carry expected and Carry obtained by summation. I didn't understand this concept, can you please explain me?
2) VHDL. This question is simple, I think. In all example in the books, when a flip-flop is present, the rising edge of the clock is managed in this way: process(clk), and then for expalin the rising edge there is a line "if(clk'event & clk = 1)". The question si: why "clk'event" is necessary? The signal clk is inside the process, so we go inside the process each time the clock change its state, isn't sufficient to evalute only if clock is egual to 1, because the clk'event is Always true?