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Show 10 flop, and each transition to a single NAND gate. The forward. 1.5 Asynchrony Speed-Independence in One-Hot Circuits There currently exist two schemes for implementing control-unit state-machines using the One-Hot technique, an asynchronous scheme and a speed-independent scheme. Both scbemes have their advantages but the speed-independent scheme is much safer operationally than the asynchronous seheae , Functional simulation of asynchronous control-unit state-machines requires a true logical simulator with good delay analysis capabilities. Sine asynchronous machines can fail because of non-uniform delays and hazards due to non-fundamental mode arrival of input Signals, simulation of asynchronous machines is complex and requires detailed rise-time and fall-time analysis of the individual gates which form the state-machine. Functional simulation of speed-independent control-unit state-machines requires only sequence information. Since no transitions can occur until the machine is ready, the exact timing of input arrivals is not needed to ensur-e correct operation of the machine. The following sections detail the operation of both the asyncbr-cnous and speed-independent one-hot schemes. 1.5.1 The Asynchronous One-Hot Scheme The asynchronous one-hot scheme is described by Hollaar [38]. It -- consists of mapping each state to one cross-coupled NAND-gate flip- |
