From db4375e9e699653321252af43d6fa2db214a77ad Mon Sep 17 00:00:00 2001 From: Cao Sen Miao Date: Fri, 14 Apr 2023 11:39:12 +0800 Subject: [PATCH] docs: Add more content about 32bits address flash usage --- .../peripherals/spi_flash/spi_flash_optional_feature.rst | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/docs/en/api-reference/peripherals/spi_flash/spi_flash_optional_feature.rst b/docs/en/api-reference/peripherals/spi_flash/spi_flash_optional_feature.rst index b51f9912a8..7ead7b2bf8 100644 --- a/docs/en/api-reference/peripherals/spi_flash/spi_flash_optional_feature.rst +++ b/docs/en/api-reference/peripherals/spi_flash/spi_flash_optional_feature.rst @@ -123,3 +123,11 @@ Flash Chips List: 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 `CONFIG_SPI_FLASH_32BIT_ADDRESS` and read the limitations following: + + 1. This option only valid for 4-line flash. Octal flash doesn't need this. + 2. Only MMU on ESP chip that supports mapping to a range over 16MB memory supports this config. (Only ESP32S3 supports this up to now) + 3. This option is experimental, which means it can't use on all flash chips stable, for more information, please contact Espressif Business support. \ No newline at end of file