Still in the prototype verification stage, it’ll be a bit longer. I just found something that I want to rework (polarity protection on the 9V).
Do you have any use for ddr1/2/3?
Not really, no. Just DDR4.
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Thanks! I’m not sure if I want to pursue the older modules, so if anyone really needs them please let me know.
I was able to use the DDR5 adapter to bring one module back from the dead. It had a non-responsive SPD, so I replaced it with a new one. I was then able to use the adapter and a cheap ESP32 board to write the NVM data from another good module.
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Nice! That’s awesome.
If both modules are in the same motherboard you may want to increment the serial number to be unique and update the CRC. It sounds like it worked for you though!
Good point. I’ve only been testing one at a time.
The one I repaired does work, but it won’t boot unless I disable memory training (i.e. enable memory context restore). That is still a bit of a puzzler.
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Maybe settings in the SPD hub volatile memory instead of the eeprom? A few of them are actually non volatile (saved between power down). Off hand I don’t recall, maybe it is only write protect bits.
Is there also an issue with the PMIC?
There is no issue with the PMIC that I could see. I dumped the registers from both SPD and PMIC and they were identical for both modules, except for a couple of SPD values. I’ll investigate those.
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Trying again for the final rev of DDR4 board. The last tweak is reverse polarity protection for the 9V external supply. Seemed like a small touch that might avoid some future issues.
PCBs and components purchased, should have it before end of year.
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These are readily available 9V to 2.5 (not 2.54mm) JST connector. Instead of the weird plastic leather and cardboard type of 9V clip, I got the version with a plastic body. Unfortunately that seems to have it’s own foibles (feels a clunky, the plastic creaks and snaps a bit).
Given that this is probably going to be a very low volume board I think this is probably sufficient.
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Is there an ETA on the DDR4 board yet?
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I can give you an update tomorrow. I’d guess a few weeks because of Chinese new year.
The final revision just arrived. I’ll test it and if everything is OK it will go into production next week.
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- DDR4 adapter tests with SODIMM and UDIMM went fine.
- The VPP (programming voltage control) works as expected.
- The feedback voltage (IO3) also looks good: 3.4v x ((5600+3300)/3300) = 9.17V (using a 9 volt block battery).
This is good to go, we started initial batch production today.
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I don’t see this one on the order site yet. Should it be there soon?
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It’s spring festival in China so everything is shut down at the moment. I believe we’re just waiting on the professional photos, so it’s coming very soon. Expect an update in a week or so.