How to Visually Tell New from Old Silicon?

[laserguy]

I'm starting to see ESP32 modules & boards on eBay and elsewhere again, so can I assume the "fixed" silicon promised for Feb. 2017 is now in full production?

If so, I have an IMPORTANT QUESTION, which I believe others would like to know as well...

What are the differences in physical markings (i.e. - date codes, etc.) to VISUALLY distinguish between the old and new version?

While info on bare chip codes will also be useful, what I am PARTICULARLY interested in is the differences in markings for the Espressif ESP-WROOM-32 (as you can't read the #'s on the chip when it's inside a canned module!).

The reason I ask, is that now that the fixed chip is available, there are going to be some suppliers that will try to dump their old inventory by falsely claiming it is new, so people need to know how to visually distinguish between the two versions.

Thanks!

[ESP_igrr]

It's possible to distinguish them by date code, i'll get back to you on the exact week number for the last non-ECO chips. We will also update the ECO document with this info.

[ESP_igrr]

All chips with date code after 1714 are guaranteed to be post-ECO.
Prior to that date code, we can only tell by PO number. Please contact sales directly for this.

For modules, we don't have any way to identify them yet, other than by running some code, or by the factory-programmed MAC address.

[WiFive]

All chips with date code after 1714 are guaranteed to be post-ECO.
Prior to that date code, we can only tell by PO number. Please contact sales directly for this.

For modules, we don't have any way to identify them yet, other than by running some code, or by the factory-programmed MAC address.

Isn't the date code for chips WWYYYY so week 14 (142017) is April 3, can that be right?

For wroom32 there is a number 211-161007. Is this a date code YYMMDD? EDIT: no this is a telec certification number. We know at least modules with no FCC/CE markings are old revision.

Are any wrover modules being made with rev0? Seems probably not because of SRAM bug.

[madscientist_42]

Odds are good that something with THAT particular date code is a first rev device. 10/16/2016 date code precludes, per the docs, a second revision part in your module.

Mine was bought as recently as Feb from Adafruit- and has that datecode. (Grumble...) Some of those bugs aren't show stoppers, but they're VERY annoying. Seriously. The only show stopper for me is the BOR not working on either rev. Is it going to be working on the third cut of these parts? I can live without it working for now, but I'd like to know if there's needing to be my own brownout answer in any designs I might ultimately field for my personal/pet projects.

I strongly suspect that unless you're buying a WROOM unit, you're likely as not to get first revision silicon for a bit yet to come.

[rudi ;-)]

hi guys
btw, i did the same mistake:

if we talk from the revision of esp32 and just in time the actually revision,
this is named with silicon revision 0

the new revision of esp32 has the revision 1 and release date 2017.02

part_of_eco_and_workarounds_chip_revision.jpg (45.7 KiB) Viewed 25384 times

src side 4

we canread this by software and efuses

chip_rev_code.jpg (40.61 KiB) Viewed 25384 times

best wishes
rudi

[ikerbelloso]

rudi , is that information from EFUSES fully trustable? The piece I have was supposed to be silicon version 1 and I'm reading 0.

[rudi ;-)]

rudi , is that information from EFUSES fully trustable? The piece I have was supposed to be silicon version 1 and I'm reading 0.

if you not get this "sample" piece explicitly from espressif, then i think you only have Rev 0
cause the silicon Rev 1 is "just in time to go on" and example to built in in new ESP32 Modules "Wrover"...

what produce date is on the chip`?
from where you got this piece ?

the Wrover Module that i know with pSRAM32 is Rev 0 - its an engineer modul - was send out from epressif on christmas 2016 and there was in the past testings with pSRAM and found out PSRAM bug on this..

what i know from espressif is, that the Wrover Modules just in time are in produce and come out in May.
this was from a state of my last contacts with espressif directly.

ESP-WROVER-32 : Now it's Rev0.
This version is out of stock and we are producing the Rev1 which will be available in May.

best wishes
rudi

[ikerbelloso]

hi rudi
the ESP32-D0WDQ6 sample came from distribution as silicon version 1 and I've replaced into a ESP-WROOM-32 module.
the piece marking says 012017 , PC3W29. Apparently the manufacturing week doesn't ensure being V1 but, from ESP_igrr words, prior to that there were some pieces manufactured.

[rudi ;-)]

hi rudi
the ESP32-D0WDQ6 sample came from distribution as silicon version 1 and I've replaced into a ESP-WROOM-32 module.
the piece marking says 012017 , PC3W29. Apparently the manufacturing week doesn't ensure being V1 but, from ESP_igrr words, prior to that there were some pieces manufactured.

012017 is devinitiv Rev 0

rev_0_s.jpg (72.24 KiB) Viewed 25128 times

best wishes
rudi

edit:
btw: PC3W29 is the batch id of "silicon wafer"