Sequential synthesis and Xilinx

• Combinational logic is key to FPGA FSMs

  • Size of next-state functions
  • Critical path is combinational

• One-hot encoding

  • Minimizes # of inputs into next-state functions
  • Uses more registers
    • But simpler, faster combinational logic

• Output-based encoding

  • Register outputs are FSM outputs
    • No need for combinational logic after registers
    • Saves CLBs

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