Part(a) shows the sequence of writing three data bytes into the memory block. Note that as each new byte is written into location 1, the other bytes move to the next location. Part(b) shows the sequence of reading the data out of the FlFo block. The first byte read is the same as the first byte that was written, and so on The FIFO operation is controlled by special address pointer registers that keep track of where data are to be written and the location from which they are to be read.