Predictive timing calibration for memory devices

Abstract

The present invention provides a unique way of using a 2N bit synchronization pattern to obtain a faster and more reliable calibration of multiple data paths in a memory system. If the 2N bit synchronization pattern is generated with a known clock phase relationship, then the data-to-clock phase alignment can be determined using simple decode logic to predict the next m-bits from a just-detected m-bits. If the succeeding m-bit pattern does not match the predicted pattern, then the current data-to-clock alignment fails for a particular delay value adjustment in the data path undergoing alignment, and the delay in that data path is adjusted to a new value. The invention also ensures that data alignment will occur to a desired edge of the clock signal, e.g., a positive going edge, by forcing a failure of all predicted m-bit patterns which are associated with an undesired edge, e.g., a negative going edge, of the clock signal.

Dependencies are inferred from the claim text.