SK-AM62: How to reduce DDR CLK

You need to use the DDR Register Configuration tool: https://dev.ti.com/sysconfig/?product=Processor_DDR_Config&device=AM62x to generate a new configuration file.  

I think you can start with the default configuration for the AM62x board (choose Reference Design: SK-AM62B-P1 with MT40A1G16KD-062E IT:E), If you want to reduce frequency, you can do so in the System Configuration section, just change to something like 600MHz, and the rest of the parameters will change automatically.  Save the new .dtsi file and rebuild your code.  

If it still doesn't work, you might need to change some of the IO settings because of the new device.  Let me know if this is the case.

Regards,

James

Hello ,JJD, I greatly appreciate your reply.

I followed your method step by step to configure it to clk=600M, then save the new .dtsi file and rebuild my code.but it still doesn't work. The new device is H5ANAG6NCJR-xxCIs it true that this new device requires modifying the IO settings, as you mentioned? I have no experience modifying DDR parameters. Could you please guide me on how to make the necessary modifications? I would be very grateful.

Hi George,

nothing in the datasheet will help with proper termination and drive strength settings, these would typically come from board simulations to derive the most optimal settings.

Just to verify, are you simply replacing the DDR4 on the TI EVM with the Hynix device?

Let me go thru the hynix datasheet, there may be some tweaks that are necessary.  

In the meantime, can you add the patch described here: https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1358039/faq-board-bring-up-tips-for-sitara-devices-am64x-am243x-am62x-am62l-am62ax-am62d-q1-am62px#:~:text=Getting%20DDR%20register%20dump%20after%20initialization

This will dump DDR register configuration after init and will help facilitate debug and what specifically is going wrong with the DDR init.  Please post this register dump

Regards,

James

Hi George, 

the Hynix device may not be exactly compatible.  I just noticed this statement in the datasheet: " DBI(Data Bus Inversion) is supported(x8)"

which implies that DBI is only supported for the x8 packages.  Since you are using the x16 package, you would have to disable Read DBI.  I have done this in the attached configuration, please try with this config:

/cfs-file/__key/communityserver-discussions-components-files/791/k3_2D00_am62x_2D00_ddr_2D00_config-_2800_34_2900_.dtsi

Note that we recommend using DDR4 devices which support read DBI (which the Micron device does) to reduce power supply noise.  You may need to check with Hynix to verify support for read DBI.

Regards,

James