Low Power and High Performance Asynchronous Pipeline Primitive Circuits for Complex-Topology Interconnection Networks

Lead Inventors: Steven M. Nowick, Ph.D.Problem or Unmet Need:Nearly every current digital system utilizes a synchronous architecture where a global clock provides for centralized timing control. This type of design strategy "synchronizes" all of the individual components, thereby forcing them to operate at the same fixed rate. However, as high performance digital systems continue to evolve and become more complex, digital design with a single centralized clock will become far less tractable and convenient. Asynchronous systems provide an attractive alternative design strategy wherein each component is allowed to operate at its own rate. This invention enables high-performance asynchronous architectures by providing fundamental new digital system components. The invention describes two new cells or basic components that are generally applicable in asynchronous pipelines. The first component is the fanout or split cell, which receives one signal as input and yields two signals as output. Instead of transmitting the input signal into both output channels, the fanout cell transmits the signal into only one of the output channels when prompted by a control element. This cell effectively serves as an asynchronous pipeline demultiplexer, a circuit element that receives a single input signal and chooses one of several output channels. The second component is the fanin or merge cell, which receives two signals as input and yields one signal as output. Instead of waiting for both input signals, the fanin cell uses an arbiter to select the arrived signal and direct that signal to the output channel. If the second signal subsequently arrives, it is also directed to the output channel. This cell effectively functions as an asynchronous pipeline multiplexer, a circuit element that selects from many input signals to yield a single output.

In asynchronous systems, the new components:1. afford reduced wait times and higher throughput data processing 2. only use power on demand thereby decreasing overall power consumption 3. provide improved scalability and robustness for the entire architecture 4. enhance overall performance by imparting new data routing capabilities 5. allow for safe and controlled demultiplexing and merging of data streams

The asynchronous system components could be used in consumer electronics that operate with asynchronous chips i. e. pagers, cell phones, smart cards, and digital passports. The new components are viable in other asynchronous systems under development, which include ethernet routing chips, digital sensors, and computer interconnects. Since nearly every current synchronous digital system can be potentially converted to an asynchronous architecture, the new components have widespread applicability in digital circuits.

The invention describes two new cells or basic components that are generally applicable in asynchronous pipelines. The first component is the fanout or split cell, which receives one signal as input and yields two signals as output. Instead of ...

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