Abstract: The system and method of the present invention provides an innovative bus system of lines which can be programmed and to provide data, control and address information to the logic circuits interconnected by the bus system. This flexible structure and process enables a configurable system to be created to programmably connect one or more logic circuits, such as megacells. The programmability of the bus system enables the cascading of multiple megacells in an arbitrary fashion (i.e., wide, deep or both) and the sharing of common lines for system level communication.

Abstract: A programmable logic device which incorporates an innovative routing hierarchy consisting of the multiple levels of routing lines, connector tab networks and turn matrices, enables an innovative, space saving floor plan to be utilized in an integrated circuit implementation, and is particularly efficient when an SRAM is used as the configuration bit This floor plan is a scalable block architecture in which each block connector tab networks of a 2.times.2 block grouping is arranged as a mirror image along the adjacent axis relative to each other. Furthermore, the bidirectional input/output lines are provided as the input/output means for each block are oriented only in two directions (instead of the typical north, south, east and west directions) such that the block connector tab networks for adjacent blocks face each other in orientation. This orientation and arrangement permits blocks to share routing resources. In addition, this arrangement enables a 4.times.4 block grouping to be scalable.

Abstract: A bidirectional passgate switch for connecting two conductors utilizes technology such as electrically erasable programmable read only memory (EEPROM). The switch includes two EEPROM components wherein the floating gates of the components are shared. In one embodiment a first n-channel passgate transistor is used for programming and storage of the state of the switch. The oxide of the first transistor is a thin oxide to enable ease of programming. A second n-channel passgate transistor functions as the bidirectional switch wherein the source and drain terminals are coupled to the routing lines to be selectively connected. The second transistor oxide is a thick oxide to minimize the leakage due to tunneling. Thus, the programming lines and routing lines are separated, making the programming process simpler while minimizing leakage.