Derek Roberts

Assessment of the performance of zener references of the highest quality

Zener diodes are now playing an important part in the development of transfer voltage standards. The computer-controlled equipment that is described is capable of measuring these devices to 1 part in 107 at the 6-V level. A technique is described for characterizing the data obtained at various currents and temperatures in order to produce quantitative figures for the important parameters of zener diodes. The results and application of this method are discussed.

TRIPWIRE: A SYNCHRONISATION PRIMITIVE FOR VIRTUAL MEMORY MAPPED COMMUNICATION

Existing user-level network interfaces deliver high bandwidth, low latency performance to applications, but are typically unable to support diverse styles of communication and are unsuitable for use in multiprogrammed environments. Often this is because the network abstraction is presented at too high a level, and support for synchronisation is inflexible. In this paper we present a new primitive for in-band synchronisation: the Tripwire. Tripwires provide a flexible, efficient and scalable means for synchronisation that is orthogonal to data transfer. We describe the implementation of a non-coherent distributed shared memory network interface, with Tripwires for synchronisation. This interface provides a low-level communications model with gigabit class bandwidth and very low overhead and latency. We show how it supports a variety of communication styles, including remote procedure call, message passing and streaming.