Does T2080RDB support non ECC DRAM?

[craigdehaan]

Can anyone confirm whether or not the T2080RDB works with non ECC DRAM? I tried replacing the SO-DIMM with one that is the same speed except it does not have ECC. I set ecc=off in the hwconfig variable in U-Boot. The ECC module works (and U-Boot prints out that ECC is turned off), however the non ECC module does not work. I used the ddr_interactive U-Boot variable to stop it in the boot process and look at the DRAM controller registers for both modules and they are the same. It seems to me that the board doesn't support non ECC modules for some reason but I would like to get a confirmation of this.

[craigdehaan]

See attached log files.

[ufedor · Accepted solution]

In DDR3 /3L the SoDIMM with ECC and the SoDIMM without ECC are not pin compatible. That means if a given board can only supports DDR3/3L SoDIMM with ECC or support SoDIMM without ECC. A given board cannot support both SoDIMM with and without ECC.
The T2080RDB board was designed for SoDIMM with ECC. It will not work with a SoDIMM without ECC. FYI, The pin incompatibility in DDR3 SoDIMM between with ECC and without ECC is defined by JEDEC and not NXP. This problem was resolved for DDR4, that means in DDR4 SoDIMM with ECC are pin compatible with SoDIMMs without ECC.  

[ufedor]

Please provide (as attachments) logs for ECC- and non-ECC SODIMMs similar to shown in the:

u-boot/README.fsl-ddr at 503eff00a7119d2690a662ed64e83e4782b7d3d9 · qoriq-open-source/u-boot · GitHu...