AR# 39767: MIG Reference Design for ML605 Board Fails Calibration During Reconfiguration
MIG Reference Design for ML605 Board Fails Calibration During Reconfiguration
The MIG Reference Design for the ML605 board intermittently fails during Write Leveling reconfiguration. Other MIG designs run on the ML605 board also fail during other stages of calibration reconfiguration.
These failures are a result of a voltage spike occurring on the VCC15V rail during reconfiguration, which causes an Over-Voltage (OV) Fault to occur on the TI Power Controller.
This temporarily shuts off power to the DDR3 1.5V power rail during reconfiguration, which then causes the incorrect DDR3 initialization sequence, and then causes various stages of calibration to fail.
The OV Fault threshold is set to a conservative value of 1.65V while the DDR3 has an absolute maximum rating of 1.975V.
Setting the OV Fault threshold to 1.85V resolves all calibration problems during reconfiguration.
This might or might not affect custom boards, so we recommend customers consult with their power system vendor to determine the loading and dynamic response required when designing their own system power solution.
The ML605_TI_Power_OV_1_85.zip provided below contains a .xml file that can be used to increase the OV fault threshold to 1.85V.
Also provided is ML605_TI_Power_Factory_Default.zip, which contains the .xml file with the factory defaults in case you need to revert the threshold back to 1.65V.
The TI_power_DPD_mfrsGUI.pdf pages 24-29 contains the necessary steps for running the .xml scripts to change the threshold in the power controller.
The PDF is included in the TI_power_DPD_mfrsGUI.zip file referenced below.
You will need to download Texas Instruments' Digital Power Manufacturing Tool, which is free, and use a USB Interface Adapter to communicate with Texas Instruments' Power Controller on the ML605.