Vuman is a wearable portable computer used for navigation through electronic blueprints. Thirty working units of Vuman were designed and manufactured from system concept using a concurrent engineering design environment. The authors describe the steps in prototyping Vuman, using the suite of synthesis and analysis tools in the electronic and mechanical domains which comprise the concurrent engineering design environment. Some unforeseen problems and their proposed solutions are discussed.>

A general approach for synthesizing inter-process communication devices by adapting labeled transition systems is proposed. An approach is also proposed to generate the finite state machine representing the protocol converter. It is assumed that the data path of the protocol converter is already given. The approach is illustrated by generating the communication process between a four phase master and a two phase slave.>

The input/otrtput (1/0) subsystem is often the bottleneck in high performance computer systems where the CPU/Memory technology has been pushed to the limit.But recent microprocessor and workstation speeds ae beginning to shift the system balance to the point that 1/0 is becoming the bottleneck even in mid-range and low-end systems.In this work the 1/0 subsystem's impact on system performartce is shown by modeling the relative performance of VAX uniprocessors with and without enhancement in the 1/0 subsystem.Tradhional system performance models were enhanced to include the effect of the I/O subsystem.The parameters modeling the I/O subsystem's effect were identified as D[,O (the number of I/O bytes transferred per instruction executed by the CPU), trl,O (the &ansfer time per I/O byte), and Wq (the waiting time in the I/O subsystem).These parameters were measured on a VAX1 1/780 system by using special purpose hardware and were used to calibrate the enhanced system performance model.It is interesting to note that these measurements indicate that contemporary systems require a factor of eight increase over the I/O bandwidth requirement stated by the Amdhal-Case rule.

Two new sets of results are presented that extend work on state assignment for multilevel logic implementation previously reported by the authors (see Proc. IEEE/ACM 25th Design Autom Conf., p.433-8, 1988). Results are presented for several state assignment algorithms that were compared using an improved logic optimization method. The resulting logic implementations were smaller in absolute size and showed considerably more variation in random state assignment than in previous experiments. A new set of experiments that compare state assignment implementations in two-level and multilevel implementations using randomly generated state assignments is reported. These experiments show that, for the benchmark set used, a state assignment that gives a good two-level implementation also gives a good multilevel implementation.>