A novel MUX-FF circuit for low power and high speed serial link interfaces

In this paper, a novel multiplexer-flip-flop (MUX-FF) topology using the current mode logic (CML) is presented. A CML multiplexer-latch (MUX-latch) is proposed by combining a multiplexer and the loopback storage part of a latch into a single module so that the buffer part of a latch can be removed. A MUX-FF is implemented by cascading two stages of MUX-latches. The output of a MUX-FF is edge-triggered, so it is insensitive to input noise. All the paths from inputs to the output are symmetric. Power and area can be reduced due to the removal of DFFs. Simulation results show that a MUX-FF can achieve a similar frequency as a conventional tree-type MUX by saving 56% of area and 72% of power consumption.