CLOCK AND DATA RECOVERY PHASE-LOCKED LOOP AND HIGH-SPEED PHASE DETECTOR ARCHITECTURE

摘要

A clock recovery circuit and a high speed phase detector circuit that operate at a clock speed equal to one-half the input data rate (i.e., a half-rate clock) are presented. The clock recovery circuit uses dual input latches to sample the incoming serial data an both the rising edge and falling edge of a half-rate clock signal to provide equivalent full data rate clock recovery. The clock recovery circuit functions to maintain the half-rate clock transitions in the center of the incoming serial data bits. The clock recovery circuit includes a phase detector, charge pump, controlled oscillation module and a feedback module. The phase detector produces information on the phase and data transitions in the incoming data signal to the charge pump. Generally, the circuit is delay insensitive and receives phase and transition information staggered relative to each other. The high speed phase detector circuit provides phase information and transition information from incoming serial data. The high speed phase detector circuit samples the incoming serial data on both the rising edge and falling edge of the half-rate clock to provide equivalent full high speed data rate sampling. The high speed phase detector circuit generates a delay between the phase information and the transition information. The phase information is produced in a first bit period and the transition information is produced in a second bit period relative to the first bit period.