AM5728: How to change frequency of DDR on AM5728

Hello Rohit,

Have you followed the recommendations and other configurations from this document?

https://www.ti.com/lit/an/sprac36e/sprac36e.pdf?ts=1686947277947

Regards

Josue

Josue Zamitiz-Ayala said:

Have you followed the recommendations and other configurations from this document?

https://www.ti.com/lit/an/sprac36e/sprac36e.pdf?ts=1686947277947

Yes I have followed this document. In this document section 3.3.2 - PLL Parameters, there are two configurations given for PLL - one for 532 MHz and other 666 MHz.  I want to configure for 400 MHz. Where can I find the PLL settings for 400 MHz ?

Josue Zamitiz-Ayala said:

Here is the example on changing DDR PLL

Linux Porting Guide for AM571x_AM570x Speed Grades - Texas Instruments Wiki.pdf

This example is showing how and where to do configurations porting in uboot and kernel.  Nothing is mentioned on how to get PLL configurations for a different frequency, say 400 MHz.

Hello Rohit,

I am consulting internally and will respond as soon as I hear back.

Regards,

Josue

Hi Josue,

Thanks for your reply. 

I understand we need to create a new structure for 400 MHz. We are not changing oscillator in our board. It is same as in AM5728 evaluation board. OS0= 20 MHz and OS1=22.579 MHz.

Can I configure DDR for 400 MHz without changing oscillator ?

Josue Zamitiz-Ayala said:

You can see the structure definition here: git.ti.com/gitweb

From the structure definition, it is not clear to me what values should be used for 400 MHz. Could you please provide any explanation guide for this structure ?

I have generated register values from EMIF tool and updated in u-boot code. But it is not giving any timing parameters as output. I have attached EMIF Tool for reference.

EMIF_RegisterConfig_edit_20210322.xlsm

Regards,

Rohit Yadav