AM625: DDR4 dual rank support

Yes, DDR4 on AM62x supports dual rank.  The app note needs to be updated to reflect this.  The DDR configuration tool https://dev.ti.com/sysconfig/?product=Processor_DDR_Config&device=AM62x can be used to generate the proper register configuration file for software.

Regards,

James

Hi James,

Thanks for your reply. I understood AM62x support dual rank DDR4.
I have two requests from my customer.
#1) Could you provide dual rank version of Figure 2-2?
https://www.ti.com/jp/lit/an/sprad06/sprad06.pdf
The customer wants to use 8bit, dual rank DDR4 chip x 2pcs.
The DDR part number is IS43QR8K02S2A-083TBLI.

#2) You mentioned sysconfig can generate required register configuration properly, but the customer found below E2E thread.
https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1191664/am625-ddr4-dual-die-support
This item was assigned to you. And it seems some modifications were needed outside of sysconfig.
Could you double check only sysconfig file is enough?

Thanks and regards,
Koichiro Tashiro 

Koichiro, i can provide the diagram, but i am out next week, so i won't be able to provide until mid May

The changes in the e2e link you sent are needed to access the extended memory range beyond 2GB.  Depending on the SDK version you are using, you will need to use the code changes mentioned until the patches are part of the official SDK releases.

Regards,

James

Hi James,

JJD said:

Depending on the SDK version you are using, you will need to use the code changes mentioned until the patches are part of the official SDK releases.

The customer uses below SDK version. Do they need to apply these changes?
ti-processor-sdk-linux-rt-am62xx-evm-08.05.00.21

Thanks and regards,
Koichiro Tashiro

Hi James,

JJD said:

Yes, they will need to apply the code changes.  

Do you know in which version of SDK will support up to 4GB DDR?
As I mentioned, the customer is planning to use two dual rank 2GB chips, total 4GB.

Thanks and regards,
Koichiro Tashiro

Hi James,

Any updates for the last question?

Thanks and regards,
Koichiro Tashiro

Hi Tashiro-san,

Since the SK-AM62 has only 2GB DDR, I don't think the SDK would by default support 4GB, since there would be no platform to validate the software.