Multi-channel multi-protocol transceiver with independent channel configuration using single frequency reference clock source

Abstract

A circuit for producing one of a plurality of output clock frequencies from a single, constant input reference clock frequency. The circuit comprises a reference clock system and a phase lock loop. The reference clock system includes a bypass path, a divider path including a first integer divider, and a multiplexer. A divisor of the first integer divider is based on a selected communications protocol of a group of possible communications protocols. The multiplexer is configured to route the bypass path or the divider path based on the selected communications protocol. The phase lock loop includes a voltage controlled oscillator and a feedback path. The feedback path includes a second integer divider. A divisor of the second integer divider is based on the selected communications protocol. The reference clock system is configured to receive a constant reference clock frequency. The voltage controlled oscillator is configured to produce one of a plurality of output clock frequencies corresponding to the selected communications protocol. The selected output clock frequency is produced based on at least one of the routing of the multiplexer, the divisor of the first integer divider, and the divisor of the second integer divider.