Intel Corporation
DUTY CYCLE ADJUSTER OPTIMIZATION TRAINING ALGORITHM TO MINIMIZE THE JITTER ASSOCIATED WITH DDR5 DRAM TRANSMITTER

Abstract:

Methods and apparatus for duty cycle adjuster optimization training algorithms to minimize jitter associated with DDR5 DRAM transmitters. Basic and Advanced Duty Cycle Adjuster (DCA) training algorithms are implemented to reduce duty cycle error and hence reduce phase mismatch translated jitter in the transmitter DQS signals. In accordance with aspects of the Basic DCA training algorithm, duty cycles for QCLK, IBQCLK, and QBCLK are adjusted by a memory controller that utilizes a DCA function implemented on a memory module (e.g., DDR5 SDRAM DIMM) to obtain a first set of optimized DCA code settings. The first set of optimized DCA code settings are then used as initial settings for the Advance DCA training algorithm to further optimize the DCA code settings for QCLK, IBQCLK, and QBCLK. A similar technical may be employed to reduce duty cycle error and jitter for DQ signals.