A FIFO memory with a frequency f and a size of M n-bit words, to successively store n-bit words received serially at an input and give said words serially at an output in the order in which they are stored, comprises a basic memory with a frequency f/2, capable of simultaneously storing two n-bit words successively received at the input of the FIFO memory. The memory also comprises a storage circuit to store either one n-bit word received at the input of the FIFO memory or simultaneously two n-bit words produced by the basic memory and to produce, at the output OUT of the FIFO memory, one of the words that said storage circuit stores.