Advanced Micro Devices, Inc.
MEMORY CONTEXT RESTORE, REDUCTION OF BOOT TIME OF A SYSTEM ON A CHIP BY REDUCING DOUBLE DATA RATE MEMORY TRAINING

Abstract:

Methods for reducing boot time of a system-on-a-chip (SOC) by reducing double data rate (DDR) memory training and memory context restore. Dynamic random access memory (DRAM) controller and DDR physical interface (PHY) settings are stored into a non-volatile memory and the DRAM controller and DDR PHY are powered down. On system resume, a basic input/output system restores the DRAM controller and DDR PHY settings from non-volatile memory, and finalizes the DRAM controller and DDR PHY settings for operation with the SOC. Reducing the boot time of the SOC by reducing DDR training includes setting DRAMs into self-refresh mode, and programing a self-refresh state machine memory operation (MOP) array to exit self-refresh mode and update any DRAM device state for the target power management state. The DRAM device is reset, and the self-refresh state machine MOP array reinitializes the DRAM device state for the target power management state.