TDA4VM: TDA4VM DDR

Hi,

There is a function in the driver included with u-boot / PDK which can read the LPDDR4 mode register.

See the driver function (lpddr4_getmmrregister) here: https://git.ti.com/cgit/ti-u-boot/ti-u-boot/tree/drivers/ram/k3-ddrss/lpddr4.c?h=08.06.00.007#n288

The function input parameter, readmoderegval, corresponds to DDRSS_CTL_160[24:8]. 

Bits ( 7:0) define the memory mode register
Bits ( 15:8) define the chip select.
Bit (16) triggers the read

See the example below, where readModeRegVal variable is set as 0x10000 | ((rank & 1) << 8) | (mr & 0xFF), where "rank" is the chip select of interest, and "mr" is the mode register number of interest. 

Regards,
Kevin