4GB DDR3 Reference design-imx6

[tamilarasane]

Hi All,

we are planning  to design iMX6 Quad with 4GByte DDR3 and Solo with 2GB DDR3  using MT41K512M16 (twin die DDR3L).

so we decided to use DRAM_CS0 (Y16)  & DRAM_CS1( AD17) of iMX6.

we feel better if we get application note / reference design for this.

is there any reference schematics with 4GB DDR3 for imx6?

Thanks,

Tamilarasan

[twmemphis]

As I see that many people would like to use 8 Gigabit DDR3 devices in their designs, I would like to update you with the current market situation, because there are lots of changes with the worldwide shortage on memory:

8 Gigabit "Twin-Die" or "Dual Die" components - having two chip-select pins - have in the past been available from Micron (MT41K512M16TNA) , Samsung (K4B8G1646D) and Hynix (H5TC8G63CMR).

But all these three manufacturers went End-of-Life or are short before their Last Time Buy Date.

2 years ago Micron also came up with a monolithic - single chip select - device MT41K512M16HA, but seems to no longer offer these in the industrial temperature range that many NXP users need. Per Microns website the Industrial Temperature devices are shown as "Contact Factory" which is a sign that they are not eager to take new orders.

8 Gigabit DDR3/DDR3L components are important not only for iMX6 users, but for the whole NXP user community.

Here is the good news:

A few week ago, Intelligent Memory (IM) announced the release of a brandnew series of 8Gb DDR3 components.

See this Link to the press release

IM has 8Gb in x16 (BGA96), but also in x8 (BGA78).

And they have BOTH, Dual Die parts with two chip-select pins, and also single-CS parts. All 8Gb DDR3 are also orderable with industrial temperature range.

x16 1CS  IM8G16D3FCB

x16 2CS  IM8G16D3FCD

x8 1CS   IM8G08D3FCB

x8 2CS   IM8G08D3FCD

Furthermore, Intelligent Memory mentioned to be working on 16 Gigabit DDR3  Dual-Chip-Select parts to become available starting in Q3/2018.  This is a good sign that there will be longevity for DDR3 in general!

There is one other manufacturer left having 8Gb "Dual Die" DDR3 parts which is ISSI. However, the pricing seems to be quite a bit higher than that of IM from what I heard.  ISSI is also about to release a new Single-CS 8Gb DDR3 device soon, but please watch the chip-dimensions! The BGA package size seems very huge per their datasheet.

Regards,

Thorsten

[gusarambula]

Unfortunately no twin-die DDR3 configuration has been tested with the i.MX6 processor.

There are two main resources for DDR implementation:

Hardware Development Guide for i.MX 6 (link below)

http://cache.freescale.com/files/32bit/doc/user_guide/IMX6DQ6SDLHDG.pdf

Application Note 4467, i.MX 6 Series DDR Calibration (link below)

http://cache.freescale.com/files/32bit/doc/app_note/AN4467.pdf

There is also the SABRE board schematic which you may use as reference although it does not provide information on twin-die configuration.

Even though the twin-die configuration has not been tested it’s theoretically possible as long as it adheres to the DDR standard - which is the case of MT41K512M16 so it should work. That being said, if in doubt I would suggest using single chip DDR memories as it implementation has been proven and there is much more information regarding layout design and calibration.

[tamilarasane]

Thank you All

Hi Gusarambula,

We already designed a  imx6 based SOM  module using  single core chip DDR3L , Micron's MT41K256M16JT-125 IT (single die) part.

1. Using  4 number of MT41K256M16JT-125 IT chips we achieved 2GB DDR3 Memory space  for Quad processor

2.And  in the same design,we mounted only 2 number of MT41K256M16JT-125 IT chips and we achieved 1GB DDR3 Memory space  for Solo processor.

we referred free scale's SPF-27392_C3 schematics as reference for above design. Thanks to freescale.

Now we would like to expand the DDR3L  Memory size using MT41K512M16 (twin die DDR3L) in the existing design itself.

Hence in the same board design with small modification we can acheive 1GB /2GB DDR3 size for solo processor  by mounting 2 number of  MT41K256M16JT-125 IT / MT41K512M16  respectively.

And 2GB/4GB DDR3 size for Quad processor  by mounting 4  number of  MT41K256M16JT-125 IT / MT41K512M16  respectively.

Now  I believe   AD17 AA11 AB17 are the additional three pads of iMX6  need to be connected to L1 , J9  and J1 of MT41K512M16 (twin die DDR3L) and J9  of MT41K512M16 should be pulled down with 240 ohm. ( BY referring free scale's SPF-27392_C3  schematics)

Thanks  micron ! it already reserved these pads (L1 J9 J1 and L9 ) in MT41K256M16JT-125 IT (single die).

Can i proceed with the above modifications in SPF-27392_C3 to achieve 2GB/4GB DDR3 in solo/QUAD respectively..?

Thanks,

Tamilarasan

[tamilarasane]

Hi ,

is there any comments on this..?

Thanks,

Tamilarasan

[gusarambula]

My apologies for the delay.

I’m glad that Micron had the good sense to make these memories pin compatible in terms of having these pins reserved on the single die option. It makes it much simpler!

As I mentioned I haven’t seen any twin-die configuration being tested but you are correct. The signals you listed would enable the second die of each memory chip. Just please double check the pull-down resistor as the DRAM_SDCKE0/1 pins should have a 10k pull down resistor.

[tamilarasane]

Thanks Gusarambula,

once we complete the layout and testing . i will update the result.

[chrishossack]

Hi Tamilarasan

I'm also planning on using 4 x MT41K512M16 to achieve 4GB on my Sabre based design. You have already saved me at least one re-spin. thank you.

From reading this post I've extracted the following hints

• AD17 AA11 AB17 are the additional three pads of iMX6  need to be connected to L1 , J9  and J1 of MT41K512M16 (twin die DDR3L)
• J9 of MT41K512M16 should be pulled down with 240 ohm
• DRAM_SDCKE0/1 pins should have a 10k pull down resistor

Do you have any other hints?

Also how did you configure the kernel/u-boot/device trees to use this new configuration?

cheers

Chris

[irfansaiyed]

Hi @Tamilarasan/@Chris/@NXP

I'm also planning on using 4 x MT41K512M16(Single Die)  to achieve 4GB on my design.

I think I don't need to use  L1 , L9,  J1  and J9 as per below attached image just replace the part as I am using single Die Part MT41K512M16 16-bit.

What you guys say ??

Thanks

[tamilarasane]

Hi ,

Due to Some reason, my design was stopped and I didn't interface  TWIN die DDR3L part( MT41K512M16 ) with SABER based Design . Now  ( after 1.5 years)  one of my iMX6 based product requires 4GB RAM.  So again I am thinking to interface TWIN die DDR3L part with saber based design. In this 1.5 years , have any body interfaced Twin die DDR3L with iMX6 using 2 Chip select? 

Any body have more information on this? NXP can you please help to complete my desing?

[SergioSolis]

Unfortunately we do not have an app note about this, but it isn't much more complicated than adding 1 or 2gb.

gusarambula can you expand on this please?

[Bio_TICFSL]

SergioSolis do you have any input on this?