[Answered] What is revision 1 of the ESP32 as it relates to PSRAM usage?

[kolban]

Reading the make menuconfig docs/notes on properties, there is reference to "Revision 1" of the ESP32 having a bug.

See for example the make menuconfig property called "CONFIG_SPIRAM_CACHE_WORKAROUND".

This spawns some questions to me that I have not previously had need to consider and am looking for community guidance.

Q1:) What is the history and timeline of ESP32 releases?
Q2:) What is the currently release version of the ESP32
Q3:) How can we tell which release of the ESP32 we are using:
- Physically by visual inspection.
- Programatically from within an ESP-IDF based application.

The answers to these questions will help me address some short term thinking such as:

"Do I need to enable these work-arounds on my board?"

[WiFive]

https://esp32.com/viewtopic.php?f=2&t=826
https://esp32.com/viewtopic.php?f=13&t=2031

[rudi ;-)]

Q3:) How can we tell which release of the ESP32 we are using:
- Physically by visual inspection.

timestamp on ESP32-D0WDQ6 chip example

122017 is devinitiv rev1

- Programatically from within an ESP-IDF based application.

application:
hello world example

Code: Select all

    /* Print chip information */
    esp_chip_info_t chip_info;
    esp_chip_info(&chip_info);
    printf("This is ESP32 chip with %d CPU cores, WiFi%s%s, ",
            chip_info.cores,
            (chip_info.features & CHIP_FEATURE_BT) ? "/BT" : "",
            (chip_info.features & CHIP_FEATURE_BLE) ? "/BLE" : "");

    printf("silicon revision %d, ", chip_info.revision);

    printf("%dMB %s flash\n", spi_flash_get_chip_size() / (1024 * 1024),
            (chip_info.features & CHIP_FEATURE_EMB_FLASH) ? "embedded" : "external");

command line tool:
see here
short:

Code: Select all

espefuse.py -p PORT summary

hope this helps.
by follow to the links pointed from WiFive there are some more infos that helps too.

best wishes
rudi