AM4376: LPDDR2 compliance test fails

The DDR experts have been notified. They will respond here.

Tsuda-san

Can you share the detailed report? I presume you have run the AM437x EMIF tool to get the right register settings. If this is not already done, can you configure the EMIF tool to match your board implementation and re-verify.

Regards, Siva

Hi Siva-san,

Thank you for quick reply.

Our customers are using the following LPDDR2.

ISSI: IS43LD32320C-25BLI
DDR clock :133MHz

www.issi.com/.../43-46LD16640C-32320C.pdf

The set value is determined using the AM43xx EMIF tool.
Since I attach it, will you check whether it is wrong?

/cfs-file/__key/communityserver-discussions-components-files/791/SPRAC70_5F00_AM437x_5F00_EMIF_5F00_Configuration_5F00_Tool_5F00_V20_5F00_custom.xlsx

Since the actual settings did not work with the attached file as it is, our customer seems to have changed as follows.

EMIF4D_SDRAM_CONFIG (0x4C000008): 0x80801A31 → 0x80801231
CTRL_EMIF_SDRAM_CONFIG_EXT (0x44E11460): 0x00000101 → 0x00000001

Best Regards,
Shigehiro Tsuda

Tsuda-san
Siva is out this week, so we will likely get back to you next week.
Sorry for the delay.

Regards
Mukul

Hi Mukul,

Thank you for the reply.
Since our customer urgently want this answers, I hope that Siva-san will return to the office and he will support it as soon as possible.

Best Regards,
Shigehiro tsuda

Tsuda-san
Yes let me remind Siva to provide some guidance on this thread asap.

Regards
Mukul

Tsuda-san

Apologize for the delay in the response. Can you provide a copy of your JEDEC compliance test report?

I see some errors in the EMIF tool that you attached to the E2E post. I'm listing all the errors here:
Step1 System Details:
- Section 1A Detail 2; you specified as 133MHz. Are you running the LPDDR2 at this lower speed? The max. speed supported is 266 MHz. Just as a side note, if this is really what you need, perhaps you could use 16-b data bus and run at the max. speed
- Section 1B, Detail 6; the selection for the speed bin shows 800. It should be set to 533 MT/s
- Step2-DDR Timings; CAS latency should be set to 4 instead of 6

Can you run the same tests with 266MHz and see if it passes the compliance check? I'll be checking this more and see if I've any additional suggestions for you.

Regards, Siva

Tsuda-san

I noticed you mention in the previous post

>>>>>>>>>>>
Since the actual settings did not work with the attached file as it is, our customer seems to have changed as follows.

EMIF4D_SDRAM_CONFIG (0x4C000008): 0x80801A31 → 0x80801231
CTRL_EMIF_SDRAM_CONFIG_EXT (0x44E11460): 0x00000101 → 0x00000001
>>>>>>>>>>>

Did these settings change the results? Are the JEDEC compliance tests done with the registers from the tool or modified values?

Regards, Siva

Hi Siva-san,

Thank you for the reply.
Yes,our customer have confirmed the JEDEC compliance test with changed values.
Is there a problem as a change?
With this change, They say that memory can be accessed normally.

Best Regards,
Shigehiro Tsuda

Tsuda-san

Changing EMIF4D_SDRAM_CONFIG (0x4C000008): 0x80801A31 → 0x80801231 basically changes the CL from a value of 6 to 4. This is the right setting to be used as I indicated in my earlier post. The tool was set incorrectly.

Changing CTRL_EMIF_SDRAM_CONFIG_EXT (0x44E11460): 0x00000101 → 0x00000001 disables dynamic power down for the I/O cells. I don't anticipate this setting should change the results.

Could you help share your PLL settings for the DDR?

Regards, Siva

Hi Siva-san,

Thank you for quick reply.
Can the customer's PLL setting be obtained from the following link?

/cfs-file/__key/communityserver-discussions-components-files/791/SPRAC70_5F00_AM437x_5F00_EMIF_5F00_Configuration_5F00_Tool_5F00_V20_5F00_custom.xlsx

It will be appreciated if you confirm that there is a problem.

Best Regards,
Shigehiro Tsuda

Tsuda-san

We are unable to obtain the PLL configuration from the EMIF tool output. Can you please share the GEL file or any other code that you are using for the DPLL DDR setting?

Regards, Siva

Hi Siva-san,

Thank you for quick reply.
Our customer uses the u-boot.
I got their code, but because of their private code, I can not attach with e2e.
How do I send it to you?

Best Regards,
Shigehiro Tsuda