STM32MP151 custom PCB schematic follows STM32 getting started schematic connection

[Fieldmouse]

I making a custom ST32MP151 board with Nordic 4G, Wifi and bluettooth. I did submit a schematic and PCB review to ST via  Arrow distrubitor.

Only 2 sticking ponits. The DDR3 memeory connections I coppied from ST APP NOTE AN5031 page 38, ST now says this is wrong and should be reversed?

see attached

The other sticking point is USB connection.

There is 3 connections on ST32MP151 on ST APP NOTE AN5031 page 67.  High speed, full spped and On The Go

ST now says this is wrong and only has On The Go?

Thankjs

Dom

[PatrickF]

Hi,

regarding USB, I think the remark after your schematic review was related that in order to being able to Flashload the board, you need to use USB_DP2/DM2 connected to a PC. 

During USB boot, BootROM always use OTG IP connected to DP2/DM2.

In a solution were in final application, USBH is connected to DP2/DM2 (i.e. platform with 2 x host port high-speed and 1 port full-speed like example in AN5031), it is still possible to use a special cable (e.g. Type-A <-> Type-A) to connect a PC. BootROM only need DP2/DM2 to connect to a PC (ID and VBUS ignored).

Hard to see in your schematic abstract how many USB ports you have. if you have a single USB connector, it must be on DM2/DP2.

Regarding DDR3, schematic is not drawn to be easily readable. 

I could understand the remark is related to DQS lanes which are not connected to the right byte.

on STM32MP15, DQS0P/N should go with lower byte data (DQ[7:0]) whereas DQS1P/N should go with upper byte data (DQ[15:0]). 
If you swap bytes on memory side, DQS should follow as well.

Regards.

[PatrickF]

note also that USB should be 90 ohms differential impedance, not 600 ohms