A router circuit for selectively connecting an input terminal of the router circuit to either a specified output terminal of the router circuit (crossbar personality) or to any of a group of output terminals of the router circuit associated with a single output channel (hyperbar personality). The router circuit is made configurable as either a crossbar switch or a hyperbar switch by dividing the router chip into sections, where each section is associated with a group of input terminals, and wherein various grant circuits within each of the sections have enable/disable input terminals connected by controllable switches to either enable/disable output terminals of grant circuits in an adjacent section (hyperbar personality) or to fixed logic levels (crossbar personality). In the crossbar configuration, for each input terminal of a section, only one grant circuit per channel is enabled. Each of the sections has a different set of grant circuits enabled per channel so that no two sections can access a same output terminal of the router chip. In the hyperbar configuration, the sections are made transparent, and grant circuits are enabled or disabled depending on output wire availability. Additionally, the router circuit contains novel routing address bit and protocol bit circuitry as well as novel diagnostic circuitry for detecting broken wires between router circuits.