CIRCUIT FOR MEASURING EYE SIZE, RECEIVER FOR DATA COMMUNICATION SYSTEM, METHOD OF MEASURING THE EYE SIZE

摘要

A circuit for measuring an eye size generates first sampled data by sampling received data with recovered clock signals and generates second sampled data by sampling the received data with shifted clock signals, in which the recovered clock signals, having different phases, are recovered from the received data. The shifted clock signals are obtained by shifting each phase of at least one of recovered clock signals by respectively predetermined phases. The circuit generates error counts for calculating the eye size of the received data by comparing the first sampled data and the second sampled data and measures the eye size by obtaining a phase range where the error counts are equal to zero. Therefore, the circuit may measure the eye size without interference of frequency offsets and/or jitter of the received data.