iMX6D DDR Calibration problems

[devil0618]

Hello,

Greeting.

I have developed a customed IM6 Dual board with 2GB  DRAM(4 pieces MT41K256M16TW-107IT:P DDR3 chips by Micron).After configurating the DDR parameter,we tried DDR Stress test using DDR Stress test Tool V1.03 .The configuration progress stucked after starting DQS gating calibration,and the calibration didn't go any further.And it didn't report any "ERROR ".We also tried connecting the board with PC using a USB cabel ，the “MsgTools” can find a device,but  can't load the Uboot. We had reviewed the hardware design by "Check List".

Does anyone have any idea what I could be doing wrong or give me some suggestion? Thanks in advance for any help.

[igorpadykov]

Hi 许 

please look at suggestions ptovided on similar issue in

DDR3 configuration for imx6q processor 

Best regards
igor
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[devil0618]

Hi igorpadykov

Thank you for your advice.I have re-check my schematic files.I find THE  "USB_H1_VBUS" pin is left unconnected. And  the voltage of pin "VDDUSB_CAP" is just 1.5V. We havn't use the "USB Host " function.The  "USB_H1_DP" pin and  "USB_H1_DN"pin are also left unconnected. Do u think it's relevant to my problem.

Thanks again.

Best regards

Xu Lei

[igorpadykov]

USB_H_VBUS or USB_OTG_VBUS should be powered for having

correct VDD_VBUS_CAP, according to Figure 50-1. Power system overview i.MX6DQ RM

http://www.nxp.com/docs/en/reference-manual/IMX6DQRM.pdf 

Best regards
igor

[devil0618]

Oh my.What can i do to save this board? Is there any other way to load the uboot fils into the IMX6 processor，like JTag.Can u give me some advice.

Thanks again for your enduring reply.

Best regards

Xu Lei

[igorpadykov]

yes it is possible to load the uboot with jtag, please check AN5229

https://www.nxp.com/docs/en/application-note/AN5229.pdf 

Best regards
igor

[devil0618]

Problem solved。It was the PCB soldering issue.Thanks anyway.

[igorpadykov]

Hi Xu

yes if voltage of pin "VDDUSB_CAP" is just 1.5V then it may cause that
MfgTool can't load the Uboot. 

Best regards
igor

[devil0618]

Hi igorpadykov 

But does the pin "USB_H1_VBUS" must be connected to a 5V voltage even we don't use  the "USB Host " function? 

Best regards

 Xu Lei