Virtual channel data distribution system for integrated circuit tester

Abstract

An integrated circuit tester includes a node for each terminal of a device under test. Each node includes a pin electronics circuit for carrying out test activities at the device terminal and a vector memory system for supplying a vector sequence to the local pin electronics circuit for controlling its test activities. To program the tester, a host computer transmits an appropriate set of vectors to each vector memory system via a common bus. Before sending vectors to the vector memory systems, the host computer sends them control data assigning each to one or more 'virtual channels' such that all vector memory systems that are to receive a similar set of vectors are assigned to a similar virtual channel. Also, before transmitting each set of vectors on the bus, the host computer broadcasts additional control data to all vector memory systems designating one virtual channel as active. Thereafter only those vector memory systems assigned to the active virtual channel accept the transmitted vector set. Thus the host computer can concurrently write the same set of vectors to more than one vector memory system when the pin electronics circuits they control are to carry out similar test activities.