A dynamic DFI-compatible strobe qualification system for Double Data Rate (DDR) physical interfaces

In this work a dynamic strobe masking system (DSMS) for DDR memory interfaces is presented which works with existing DFI signals to provide dynamic masking and produces a clean strobe suitable for data capture, making it the first dynamic DFI-compatible strobe qualification system. This DSMS scheme produces a masking signal to qualify the expected pulse stream on the DQS line, thus masking out other spurious activity. Post layout simulation results in TSMC 90nm process validate the proposed masking system in the 200–533MHz range, meeting the mask shut-off specification in best, typical, and worst case corners.