SPRUJ28E November 2021 – September 2024 AM68 , AM68A , TDA4AL-Q1 , TDA4VE-Q1 , TDA4VL-Q1
I/O pad calibration runs at initialization time by default but it can also be programmed to operate in a background mode after initialization. Bits [3:1] of the DDRSS_PHY_1330[12-0] PHY_CAL_MODE_0 field enable the periodic calibration mechanism and determine the base clock frequency of the interval counter. The DDRSS_PHY_1331[31-0] PHY_CAL_INTERVAL_COUNT_0 field then sets a timer to indicate how frequently calibration is performed. When the timer expires, the calibration runs in background, independent of other traffic running through the PHY. When the calibration is complete, the updated PVTP/PVTN/PVTR codes are transferred to the PHY I/O cells. Whether or not the update of the memory clock PVTP/PVTN/PVTR codes is applied at the same time as the remaining I/O cells is controlled through the DDRSS_PHY_1298[8] PHY_CONTINUOUS_CLK_CAL_UPDATE bit. If the automatic update of the memory clock codes is disabled through the PHY_CONTINUOUS_CLK_CAL_UPDATE bit, the DDRSS_PHY_1298[0] SC_PHY_UPDATE_CLK_CAL_VALUES bit can be used to trigger a manual update.