Patent ID: 7812634

Claim:
Transceiver circuitry on a programmable logic device integrated circuit comprising: a plurality of circuit modules, each of which includes: (1) a plurality of channels of transceiver circuitry; (2) a clock source circuit; (3) a first clock signal distribution circuit extending from the clock source circuit to all of the channels in the module; (4) a second clock signal distribution circuit extending to all of the channels in the module; and (5) selection circuitry associated with each of the channels for allowing that channel to select a clock signal from either the first or second clock signal distribution circuit; first routing circuitry for allowing either the first or second clock signal distribution circuit of each module to supply a signal to the second clock signal distribution circuit of a first adjacent one of the modules; and second routing circuitry for allowing either the first or second clock signal distribution circuit of each module to supply a signal to the second clock signal distribution circuit of a second adjacent one of the modules.