Synchronous FIFOs are the ideal choice for high performance systems due to their high speed of operation. Synchronous FIFOs also offer many other benefits that improve system performance and reduce complexity. These include state flags: synchronous flags, flags almost full and almost full, almost full. These FIFOs also include features such as, width expansion, depth expansion, and retransmission. Synchronous FIFOs are easier to use at high speeds because they use free-running clocks to control internal operations while asynchronous FIFOs require read and write pulses to be generated without an external clock reference.
A synchronous FIFO describes the FIFO design in which data and information are stored in memory and transfer data in an appropriate manner using a clock pulse. Operation of reading and writing operation by control circuit. In computer programming, FIFO (first-in, first-out) is an approach to handle queue or stack program job requests so that the oldest request is handled first. In hardware it is an array of flops or read / write memory that stores data given from a clock domain and, upon request, supplies the same data to another clock domain following the first-out logic first. Basically FIFO divided into two categories as Synchronous and Asynchronous. In synchronous FIFO, the write operation to the FIFO buffer and the read operation from a same FIFO buffer occur in the same clock domain. But in asynchronous FIFO these two operations write and read to and from FIFO buffer respectively in the different clock domain. Of course the clock domain is different in asynchronous FIFO. The write operation occurs in one clock domain, and the read operation is in another clock domain.