1. PAL22IP6-25, interface protocol asynchronous cell (IPAC) PAL device,1990
2. Clock-free macrocells simplify asynchronous system design;Bursky;Electronic Design,1988
3. Self-clocking PLD implements asynchronous interfaces;Wilson;Computer Design,1988
4. Asynchronous sequential switching circuits;Unger,1969
5. Generation of a clock pulse for asynchronous sequential machines to eliminate critical races;Bredeson;IEEE Trans. Comput.,1971