After ESP-IDF 1.0...

[Ritesh]

Great work getting 1.0 out. I'll keep patiently waiting on I2S but I was hoping to hear a little news as far as external SRAM.

At the moment, it's possible to use external SRAM as a normal SPI device. We have code ready to use it as normal, internal RAM as well, but the current versions of the chip have a bug in it which introduces unpredictable errors in the data. We'll release this as soon as the chip revision that fixes this bug is on the market.

Hi,

Can you please explain what is issue in current ESP32 chip as you have told that you are going to release new ESP32 chip? Because, we have already started our product development as per current ESP32 chip which is available into market.

So, Please let us know if Espressif are going to release any new version of ESP32 chip so that I need to plan if there is major issue in current chip which breaks any functionality.

[ESP_igrr]

Ritesh, there is a document which explains silicon bugs present in the first revision of the chip: http://espressif.com/sites/default/file ... p32_en.pdf

Adding to what ESP_Sprite said about using external SRAM in the current revision:
It is possible to use external SRAM with the first revision and map it into data address space, but care should be taken to access data stored therein in a very control fashion. Reads and writes should not be interleaved. Memory bars should be placed between reads and writes. Care should be taken not to disrupt read or write patterns due to control flow or interrupts. In general, this can be achieved for some applications such as audio or imaging, where access patterns to data are very predictable (you can know exactly when you are going to read or write something). Placing general purpose heap memory into the external SRAM should not be done in the first silicon revision.

Edit: new silicon revision should become available in February. Allow some time for the new revision to make its way into the supply chain.

[Ritesh]

Ritesh, there is a document which explains silicon bugs present in the first revision of the chip: http://espressif.com/sites/default/file ... p32_en.pdf

Adding to what ESP_Sprite said about using external SRAM in the current revision:
It is possible to use external SRAM with the first revision and map it into data address space, but care should be taken to access data stored therein in a very control fashion. Reads and writes should not be interleaved. Memory bars should be placed between reads and writes. Care should be taken not to disrupt read or write patterns due to control flow or interrupts. In general, this can be achieved for some applications such as audio or imaging, where access patterns to data are very predictable (you can know exactly when you are going to read or write something). Placing general purpose heap memory into the external SRAM should not be done in the first silicon revision.

Edit: new silicon revision should become available in February. Allow some time for the new revision to make its way into the supply chain.

Thanks for Reply.

Got it. It will just affect to external RAM but I can use Internal RAM without any issue. correct?

[bennettmarks]

Really hoping to get a good DMA based SPI driver...

[ESP_Angus]

Got it. It will just affect to external RAM but I can use Internal RAM without any issue. correct?

Correct, this only applies if you attach a SPI PSRAM/SRAM chip to the ESP32 and want to map it as additional RAM.

[Ritesh]

Got it. It will just affect to external RAM but I can use Internal RAM without any issue. correct?

Correct, this only applies if you attach a SPI PSRAM/SRAM chip to the ESP32 and want to map it as additional RAM.

Thanks for Reply.

As we have already planned to create one product based on current ESP32 chip which is available into market and our product will be long term as per planning.

So, does it create any impact on older ESP32 chip production or Life Time if newer version of ESP32 chip will come into market?

Please let me know if you have idea or any informations for this so that we can plan for our product and will take decision based on chip EOL.

[ESP_Sprite]

The ESP32 won't go EOL any time soon (I think we guarantee availability for 12 years). This is just a revision; it has all the features of the current chip but fixes a bunch of bugs that e.g. stop the current chip from properly using SPI SRAM as fully-featured memory. If your application works with the current ESP32, it will work with the revised version as well, without even so much as a recompile.

[Ritesh]

The ESP32 won't go EOL any time soon (I think we guarantee availability for 12 years). This is just a revision; it has all the features of the current chip but fixes a bunch of bugs that e.g. stop the current chip from properly using SPI SRAM as fully-featured memory. If your application works with the current ESP32, it will work with the revised version as well, without even so much as a recompile.

Thanks for Reply.

That is good but for that we need to revise our schematic as well if new version of ESP32 will be released by Espressif System. But, I just want to know that will Espressif Systems stop production of older chip and replace with newer chip?

That is my concern regarding this newer chip.

[ESP_Sprite]

There is no need to change anything at all. The new revision of the ESP32 is in all senses compatible with the old version. Around February, the places that sell ESP32s will just gradually sell the new version. If you don't do anything that does not work because of something in the errata list, you don't need to change anything at all.

[Ritesh]

There is no need to change anything at all. The new revision of the ESP32 is in all senses compatible with the old version. Around February, the places that sell ESP32s will just gradually sell the new version. If you don't do anything that does not work because of something in the errata list, you don't need to change anything at all.

Yes. You are correct that no need to change anything after replacing ESP32 chip.

But, I just want to know that till how-many years or months older ESP32 chip will be available into Market once new ESP32 version supported chip will be available into market?