What are "OTFA" and "SFA" parameters for EMC configuration registers?

according to the Tegra X1 technical reference manual, the values of some of the EMC configuration registers (e.g. “MC_EMEM_ARB_TIMING_R2R_0”, “MC_EMEM_ARB_TIMING_W2R_0”) depend on the parameters “OTFA” and “SFA”, but those are not explained at all in the reference manual.
What are those parameters?

For reference:
The description of the “MC_EMEM_ARB_TIMING_R2R_0” reads
“R2R: The number of cycles between consecutive read commands to different devices (different chip selects). Program to ceil (EMC.REXT/DIV)-1+OTFA+SFA.”


Hi, did you meet some issues on this? Jetson TX1 is module type, customer has no need to handle this.

We are using a customized Jetson TX1 with two Samsung K4FBE3D4HM 4Gb ram chips.
They work fine with the provided EMC configuration, but only at low frequencies (e.g. 204MHz). At higher frequencies it doesn’t work and hangs.
We tried to adjust the EMC configuration to make it work at 1.6GHz.

The BCT configurations distributed by Nvidia in the Jetson BSPs all reference a tool that was used to generate the configuration (“Generated by t210_emc_reg_tool_P963 V9.6.3”).
Could that tool be used to generate configurations for the ram chips mentioned above? Is that tool available for download?

Hi, where did you get the “customized Jetson TX1”? In general, TX1 is sold in module type which means customer has no need to tune the memory in module. You should check with vendor first on that. Also the tool is not public.

We replaced the ram chips on the Jetson module with the 4Gb Samsung chips mentioned above, because we needed more than 4Gb ram for our application. It works fine at lower ram frequencies, but we would like to make it work at 1.6GHz aswell.

We looked into manually adjusting the EMC configuration, but that does not seem feasible, because some of the registers are not properly documented and some abbreviations are not explained in the reference manual.

It would be nice if Nvidia considered to publish the configuration tool mentioned in the BCT configurations from the BSP packages.