DragonBoard DDR Swap

custom_board

#1

Hello, we are using the dragonboard for development but due to size constraints we must redesign onto a smaller board. We have found that the Sandisk part (SD9DS28K-8G) on the dragonboard is end-of-life. From what i gather that second stage bootloader (SBL) that sets up the DDR timing is proprietary and only released as a binary blob. So it seems that i cannot just place any DDR chip on here and have it work, but must choose one that is compatible with the SBL. Is there anywhere i can figure out what chips are compatible with the SBL blob? I also cannot find a datasheet or anything for the sandisk to even try and find a similar part.


#2

Hi @jcc273

This is great, you are doing exactly what we had hoped people would do. Use the DragonBoard as a development system for your product, and then move over to a custom design for your final product. The teams at Arrow can help you with supplying an appropriate memory chip. SanDisk doesn’t post their datasheets on the web, you need to talk to SanDisk to get a copy of the datasheet.

The DDR settings are stored in a tiny partition called the CDT, which can be changed without rebuilding the proprietary binaries. Again Arrow can help you with this.

I will ask the teams for a suggestion for an alternate memory. One quick question, are you interested in a memory module ( called a MCP, or Multi-Chip Package) that contains both DRAM and eMMC, or would you prefer separate DRAM and eMMC chips?

Just a quick reminder, when you are designing your own board you should carefully read the design guidelines: https://developer.qualcomm.com/hardware/snapdragon-410/tools There are also third parties such as www.valydate.com that you can contract to do design verification.

Full disclosure: I am an employee of Qualcomm Canada, any opinions I have expressed in this or any other post may not reflect the opinions of my employer.


#3

@ljking,

Thank you for the quick response! That is great news that I can adjust the DDR settings. Sounds like I need to startup a conversation with arrow to get a lot of these answers. We have went through the design guidelines on that page, but I will make sure i go through them again as we go along to make sure nothing was missed : ).

We would probably prefer an MCP with the DRAM and eMMC because we are extremely space constrained, so the more parts we can cut out the better, but we may be able to fit them in separately if required. We were looking at parts in Micron’s MT29TZZZ series, but the availability for those is not good. There is availability in the MT29PZZZ, but those are LPDDR2 instead of 3 and I know the snapdragon supports that but I do not know if the SBL supports setting up for LPDDR2. If you come up with any good suggestions for available parts that would be awesome! I will talk with arrow as well and see what i can find out : ).

Thanks!


#4

We have a custom pcb using a 512MB LPDDR2. Here are the part numbers we are using

AS4C128M32MD2-18BCN
EDB4432BBBJ-1D-F-D

There were no settings required to bring up the board. Arrow did provide tools to verify ddr performance, but we did not have to run any tools to generate ddr register settings like other vendors.

Here are the issue we did run into:
1: little kernel needed to be updated to allow 512MB.
2. we have no sd card, so we needed to use a qualcomm tool called qfil to load software the first time. Arrow can provide this


#5

@Mark_Vogt,

Thanks! That is really helpful we were actually looking at some micron MCP’s that were LPDDR2, so the fact that the EDB4432BBBJ-1D-F-D worked for ya tells me those should as well. I will compare the specs for those and make sure, but yeah sounds like Arrow should have a lot of answers for us as well. I sent an email out to our FAE so hopefully he can provide me with those tools! We also will not have an sd card so it’s good to know there is a programming tool!

Thanks for the response i really appreciate it : ).


#6

The Qualcomm memory lab has qualified the following memories on the 410c Dragonboard. All should work with no issues on the 410c DragonBoard.

Kingston 8GB eMMC, 1GB DRAM 08EMCP08-NL3DT227
Hynix 16GB eMMC, 2GB DRAM H9TQ17ABJTBCUR-KUM
Micron 8GB eMMC, 1GB DRAM MT29TZZZ8D5JKEZB-107 W.95Q
Micron 8GB eMMC, 1GB DRAM MT29TZZZ8D5JKEPD-125 W.95T

Full disclosure: I am an employee of Qualcomm Canada, any opinions I have expressed in this or any other post may not reflect the opinions of my employer.


#7

Hello,

Does Qualcomm have a list of qualified LPDDR3 and eMMC devices that are in separate packages that don’t require changing the CDT settings from the Dragonboard development system. We would like to reuse those same CDT settings on a custom board, if possible.

Thanks,
David
.


#8

Hi David @whistle512

I wish I could say that we did have a list of fully qualified discrete memories for you. What I can tell you is we have just finished designing a board for use with discrete memories (separate LPDDR and eMMC chips) and we will be submitting boards and various memories to the memory qualification lab for formal qualification in the next several months.

To get you up and running, the initial DDR memory used on the board is Micron MT52L512M32D2PF-107 WT:B and it works on our board, but it has not been through the formal qualification process yet. I don’t expect qualification problems, but it is always possible that something might come up, that’s why we do the testing…

The initial eMMC part on the board is Micron MTFC16GAKAECN-2M WT with the same caveat, the part is working but not formally qualified.

I don’t think you need to change the CDT, but I haven’t had a chance to verify this.

Let me know which parts you want to use on your board and I will add them to the list of parts to be submitted to the qualification lab, however we don’t qualify every memory, particularly if the part is already at end of life.

You need to be very careful with DDR memory layout and power distribution. There are many hints in the design guidelines https://developer.qualcomm.com/download/sd410/apq8016e-processor-design-guidelines.pdf but let me know if there is anything missing and I will try to get the document updated.

Full disclosure: I am an employee of Qualcomm Canada, any opinions I have expressed in this or any other post may not reflect the opinions of my employer.


#9

Hello LJKing,

Thanks for the informative reply. Will this new design be commercially available? Will the design files be available?

Thanks,
David
.


#10

Hi David @whistle512

Yes the board will become commercially available, but not for a while. When it does become available your arrow rep will be able to get the design files for you.

I have confirmed that there is no change to the CDT for the new memories.

Full disclosure: I am an employee of Qualcomm Canada, any opinions I have expressed in this or any other post may not reflect the opinions of my employer.