Abstract: An output enable structure and a method for providing output capability to an input/output cell of a programmable logic device are shown. In one embodiment, one of two global output enable signals, a test output enable signal, and two product term output enable signals is selected for controlling an output buffer of an I/O cell. Additional pin-out flexibility is provided by routing the input signal received at an I/O pin to neighboring I/O cells.

Abstract: A programmable logic device has multiple groups of generic logic blocks. Each group of generic logic blocks is interconnected by a local routing pools. A global routing pool is provided to interconnect the local routing pools. The global and local routing pools can be implemented in volatile or non-volatile technology, such as E.sup.2 PROM technology. The programmable logic device can also be implemented as an in-system programmable logic device.

Abstract: A Computerized Mobile Two-Way Radio System is provided having microprocessor enhanced capabilities and versatility for wide area/multiple region two-way radio networks with multiple categories of users and adaptability to multiple international standards and mobile radio equipment configurations. The main elements of the system consist of (1) a microprocessor-based Control Unit, (2) a Digital Serial Interface/Link and (3) a microprocessor-based Convertible Transceiver Unit. The Control Unit provides many facilities and capabilities for the operator and the system in compact form. The Interface/Link provides a two-way path for serial data consisting of digitized audio and digital command and status signals. The Transceiver Unit is designed for operation and control over the Digital Serial Interface/Link.