Optional Features for Flash

Some features are not supported on all ESP chips and Flash chips. You can check the list below for more information.

• Auto Suspend & Resume

• Flash unique ID

• High performance mode

• OPI flash support

• 32-bit Address Flash Chips

Note

When Flash optional features listed in this page are used, aside from the capability of ESP chips, and ESP-IDF verison you are using, you will also need to make sure these features are supported by flash chips used.

• If you are using an official Espressif modules/SiP. Some of the modules/SiPs always support the feature, in this case you can see these features listed in the datasheet. Otherwise please contact Espressif's business team to know if we can supply such products for you.

• If you are making your own modules with your own bought flash chips, and you need features listed above. Please contact your vendor if they support the those features, and make sure that the chips can be supplied continuously.

Attention

This document only shows that ESP-IDF code has supported the features of those flash chips. It is not a list of stable flash chips certified by Espressif. If you build your own hardware from flash chips with your own brought flash chips (even with flash listed in this page), you need to validate the reliability of flash chips yourself.

Auto Suspend & Resume

This feature is only supported on ESP32-S3, ESP32-C2, ESP32-C3, ESP32-C6, ESP32-H2 for now.

The support for ESP32-P4 may be added in the future.

Flash Unique ID

This feature is supported on all Espressif chips.

Unique ID is not flash id, which means flash has 64-Bit unique ID for each device. The instruction to read the unique ID (4Bh) accesses a factory-set read-only 64-bit number that is unique to each flash device. This ID number helps you to recognize each single device. Not all flash vendors support this feature. If you try to read the unique ID on a chip which does not have this feature, the behavior is not determined. The support list is as follows.

List of Flash chips that support this feature:

1. ISSI

2. GD

3. TH

4. FM

5. Winbond

6. XMC

7. BOYA

High Performance Mode

This featuer is only supported on ESP32-S3 for now.

The support for ESP32-S2, ESP32-C3, ESP32-C6, ESP32-H2, ESP32-P4 may be added in the future.

OPI flash Support

This feature is only supporetd on ESP32-S3 for now.

OPI flash means that the flash chip supports octal peripheral interface, which has octal I/O pins. Different octal flash has different configurations and different commands. Hence, it is necessary to carefully check the support list.

32-bit Address Flash Chips

This feature is supported on all Espressif chips (with various restrictions to application).

Most NOR flash chips used by Espressif chips use 24-bits address, which can cover 16 MBytes memory. However, for larger memory (usually equal to or larger than 16 MBytes), flash uses a 32-bits address to address larger memory. Regretfully, 32-bits address chips have vendor-specific commands, so we need to support the chips one by one.

List of Flash chips that support this feature:

1. W25Q256

2. GD25Q256

Important

Over 16 MBytes space on flash mentioned above can be only used for data saving, like file system. If your data/instructions over 16 MBytes spaces need to be mapped to MMU (so as to be accessed by the CPU), please enable the config IDF_EXPERIMENTAL_FEATURES and BOOTLOADER_CACHE_32BIT_ADDR_FLASH and read the limitations following:

1. This feature is valid only for 4-line flash. Octal flash supports 32-bit-addr by default

2. This feature needs the MMU on ESP chip to be able to map to >= 16 MB physical address on the Flash. (Only ESP32S3 supports this up to now)

3. This option is experimental, which means it can not use on all flash chips stable, for more information, please contact Espressif Business support.