Applications of regenerative feedback in integrated circuits.

摘要

This thesis presents the use of regenerative feedback repeaters to speed up the signal propagation along RC lines and transmission lines on or at the periphery of integrated circuits. Such regenerative feedback repeaters locally regenerate the new level after detecting a transition. The local regeneration shorts out the resistive path from the input, and speeds up the transition on further nodes. This operating principle is similar to the signal propagation in nerve axons, and offers advantages in performance, power consumption, and use of resources.; The example of bidirectional, programmable interconnections through MOS transistors in Field Programmable Gate Arrays is used to introduce precharged, postcharged and complementary regenerative feedback repeaters. Through circuit simulations and measurements on a 1.2{dollar}mu{dollar}m CMOS test chip, it is shown that regenerative feedback repeaters are faster and smaller than conventional repeaters. It is also shown that there are limitations on the types of signals that can be propagated by feedback repeaters. Precharged repeaters require monotonic signals. Postcharged repeaters require pulses. Complementary repeaters can propagate both rising and falling transitions, but, to avoid metastability, require glitch-free signals. As a result, it is not possible to simply replace the inserted repeaters in a conventional FPGA by feedback repeaters, without compromising the zero error rate. Instead, non-conventional FPGA architectures in which only the correct signal types appear on the interconnection networks must be used. These architectures are more complex in hardware, and some of them require retiming of the logic implementation, which may have a considerable impact. On an equal area basis, the performance improvement of these alternative architectures is substantial, even after taking into account a large penalty factor for retiming.; It is also shown that the fast signal propagation through MOS transistors with precharged regenerative feedback repeaters can be combined with complementary pass transistor logic and elements of Domino logic, to obtain a dynamic CMOS logic family that is faster than Domino logic.; Finally, it is shown that by using a complementary regenerative feedback repeater at the receiving end of a transmission line, the driver impedance range of reliable first incidence switching can be extended compared to source-matching.