AMULET1 is an implementation of the ARM microprocessor using an asynchronous architecture. This project allows direct comparison of the performance and power efficiency of a well-established commercial microprocessor with that of an experimental design based on an asynchronous, micropipelined design. The ARM microprocessor is a traditional synchronous load/store architecture with a register-oriented instruction set that offers the necessary complexity to evaluate the key issues of an asynchronous design in a meaningful way.

In migrating a design from a synchronous to an asynchronous design, the authors report that while the power efficiency and performance of the new design are comparable to those of the synchronous version, the asynchronous control elements necessary for this design may require as much as 20 percent of the total chip area. It is worth noting that the asynchronous design of the AMULET1 does not require all instructions to meet the same execution profile, so the designers can optimize more commonly used portions of the instruction set. The results indicate that asynchronous control can be a viable design approach on a commercial scale, especially in larger designs, where maintaining global clock synchrony is increasingly difficult.