Authors : Avinash Yadlapati and Hari Kishore Kakarla
Abstract: A FIFO is a “First In First Out” memory queue between any two asynchronous domains with simultaneous write and read access to and from the FIFO, these accesses being on different clocks. The FIFO has input ports like data input (write), write clock, read clock, reset and output ports like FIFO full flag, data out (read) and FIFO empty flag. It also has control signals like write enable and read enable. The most important signals that control the FIFO operation are the write pointer and the read pointer. These pointers in the case of Synchronous FIFO operate in a single clock while in the case of Asynchronous FIFO operate in two clocks, write clock and read clock respectively. FIFO can be either Synchronous or Asynchronous. The basic difference between them is that the entire operation of Synchronous FIFO is entirely dependent on the clock whereas the write operation and read operation of Asynchronous FIFO are asynchronous to each other. In this study a Novel approach to designing an Asynchronous FIFO is used. Instead of taking a separate bit to identify whether the FIFO is full or empty, the resaerchers have used an internal signal (last operation) to identify if the FIFO is full or empty.
Avinash Yadlapati and Hari Kishore Kakarla, 2019. Design and Verification of Asynchronous FIFO with Novel Architecture Using Verilog HDL. Journal of Engineering and Applied Sciences, 14: 159-163.