The DDR memory controller is powered by the VCC_PSINTFP_DDR pins. These pins must be connected to the VCC_PSINTFP power pins and the FPD power supply. The DDR memory controller can only be reset along with the FPD using the PMU_GLOBAL.GLOBAL_RESET [FPD_RST] reset bit.
Note: Once the initial calibration sequence in psu_init.c is completed AMD does not recommend using RST_DDR_SS to reset the DDR subsystem.