SPRZ452I july 2018 – may 2023 AM6526 , AM6528 , AM6546 , AM6548
DDRSS: Independent Impedance Control for Address/Control and Data Bus Lanes is Not Available
AM65x SR 1.0
The IO impedance calibration control for the address/control segment and the data segment in the DDR PHY are incorrectly mapped to the same set of control registers. This results in requiring a common set of impedance settings for output driver impedance and on-die termination for both the address/control IO signals as well as the data IO signals. As a result, only register DDRPHY_ZQ0PR0 can be used to program output driver impedance and on-die termination for both address/control and data.
Program DDRPHY_ZQ0PR0 with appropriate values that will satisfy output driver impedance and on-die termination for both address/control and data signals. Use the DDR configuration tool to help determine the most optimal values. This tool will also facilitate the configuration of all DDR controller and PHY registers for optimal performance. Also, ensure that all layout recommendations are met as described in the AM65x DDR Board Design and Layout Guidelines Application Report (SPRACI2).