RAM limits for various i.mx6 devices

[dluberger]

Why isn't the max RAM listed on the product pages for the processors? I have to dig into each separate reference manual and even then it isn't clear from the memory map whether the value i'm looking at is the actual max RAM size.

Is there a table or chart somewhere that lists the max DDR size for each processor? I learned too late after designing my imx6ul board with an 8Gb DDR3L IC that that processor would only use up to 512MB which is too low for what I need.  I need to be able to compare each processor by types of video peripherals available (parallel LCD, LVDS, HDMI), max speed (I need 1GHz), and max RAM (as I said, I need at least 1GB but I want to know the max I can use) in order to make a better decision about which processor i should go with.

[b36401]

There should not be any issue with 1GB memory.
All i.MX6 series except SX and SLL support up to 4GB DDR chips.
SX and SLL ones support up to 2GB DDR per chip select.

Have a great day,
Victor

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

[dluberger]

I was told on this site that the UL and ULL only support up to 512MB of RAM, regardless of the physical space on the connected DDR.  That's where my concern comes from. I don't want to attach a 24Gb or 32Gb DDR (or 2 12Gb/16Gb) DDR3L ICs to the processor only to find out later that the processor won't use all of the attached RAM.

[b36401]

Please refer to chapter 33.1.1 "MMDC feature summary" of i.MX 6UltraLite Applications Processor Reference Manual
and chapter 35.1.1 "MMDC feature summary" of i.MX 6ULL Applications Processor Reference Manual:

* Density per DDR device of 256Mbits-8Gbits
* Up to 4 Gbytes of address space with configurable partitioning between CS0 and CS1 (for LPDDR2 2ch x32 up to 2 Gbytes per channel)

Have a great day,
Victor

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

[dluberger]

I had to unmark this as correct because I went back to my old post regarding RAM issues here: Custom i.mx6ul/ull board; no display, ram test strangeness 

As you can see in Igor's response, table 2-1 (memory map) for UL, ULL, and SX all show the MMDC—x32 DDR Controller memory range as 2048MB. The original reason for my confusion is that the memory calibration tool for the ULL device only allows me to select 512MB *max* as the RAM size. If I select anything other than 512MB as the density, I get the error "Density per chip select: 512MB selected density is higher than what is supported!".

I need clarification on this as soon as possible. I need to know what is the maximum physical RAM I can connect to a UL, ULL, and SoloX (SX) processor? Is it 512MB for the ULL like the cal tool is showing? Is it 2GB for any of them? the Quad processor shows 3840MB (I'm guessing that means 4GB) as the address range. Is table 2-1 only showing the memory address space for ONE chip select and therefore 2 chip selects means I get double with a dual-chip-select RAM IC or with two physical RAM ICs? 

Please help! I need to know what the actual total physical RAM limit is for UL, ULL, SX, and Quad are and how these can be connected as DD2L, DDR3L and with what combination of chip selects.  Please don't simply refer me to the reference or other manuals because these are not helpful.