Espressif ESP32-C2 (ESP8684) has been updated to v2.0 with 20 KB of additional SRAM, 100 KB of extra flash, with some improvements in terms of erase and program performance.
The ESP32-C2 was first unveiled in April 2024 with limited details, and launched in October of the same year as the ESP8684 SiP combining ESP32-C2 die with 4MB flash, as well as a few ESP8684 modules and the ESP8684-DevKitM-1 development board. The ESP32-C2 is meant to be a cost-down version of the ESP32-C3 with less RAM and peripherals, and the ESP32-C2 v2.0 slightly improved on that with parts adding X to the name: ESP8684H2X (2MB flash) and ESP8684H4X (4MB flash). Modules and devkit names are also impacted, albeit not shown yet in the screenshot below.
The part names had to be updated because chip revision v2.0 and previous chip revisions are not software-compatible, so Espressif had to update the ordering codes to distinguish between them. Changes are explained in the PCN (Product Change Notice).
The modification to the ESP32-C2 series chip described in Para 1 involves a hardware metal layer change, with the chip version being upgraded from v1.2 to v2.0. The latest ESP32-C2 v2.0 chip, when used with the updated ESP-IDF, provides approximately 20 KB of additional SRAM and around 100 KB of extra flash memory for project development (actual gains may vary depending on the specific application). Since the modules and development boards listed in Para 1 use the ESP32-C2 series chip, they have also been updated accordingly.
The ESP8684H4 and ESP8684H4X chip mentioned in Para 1 has introduced a new in-package flash as an alternative source to improve supply stability. As a result, the corresponding modules and development boards listed in Para 1 have also been updated accordingly.
The previous generation ESP8684 v1.2 requires ESP-IDF v5.0 and above, and the new ESP8684 v2.0 only works with IDF v5.4, IDF v5.3.2, v5.2.4, v5.1.5, IDF v5.0.8 and above.
Looking at the comparison table above, the actual flash capacity has not changed between ESP8684H4 and ESP8684H4X, but we can see the performance of the new flash is better. It looks like the extra SRAM and flash size may be due to firmware optimization, maybe because the driver for the new flash has a smaller footprint and/or the way the flash is handled is different so there’s less overhead, but Espressif did not make that clear. The ESP8284H2X did not get the “in-package flash” update.
The chip revision can be detected by reading the eFuse identification bit as shown in the table above. You may find more details on the ESP32-C2 upgrade page. If we visit the product page, only ESP8684H2X and ESP8684H4X are listed, so I guess that means v1.2 chip will be phased out.
Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.
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they should have updated the bluetooth version too.
The screen shot says 576k rom (I guess that means flash) and 272k on-chip sram, which I guess is after the change. It would have been nice to say this in the article.
I was (and I am still) confused by the announcement. Those are the memory/storage specs in the original announcement for the ESP32-C2/ESP8684:
The product page has not changed those values, and those numbers are nowhere to be found in the PCN. So now, I’m not sure whether the total SRAM capacity has changed, or they have been able to make some optimizations so that there’s 20KB SRAM extra for the user application. 576KB is really ROM. Flash is 2MB or 4MB.
Moar flesh!