diff options
Diffstat (limited to 'docs/library')
| -rw-r--r-- | docs/library/machine.SDCard.rst | 60 |
1 files changed, 42 insertions, 18 deletions
diff --git a/docs/library/machine.SDCard.rst b/docs/library/machine.SDCard.rst index 62da8c3c2..c4a0d5d17 100644 --- a/docs/library/machine.SDCard.rst +++ b/docs/library/machine.SDCard.rst @@ -77,24 +77,34 @@ ESP32 ````` SD cards support access in both SD/MMC mode and the simpler (but slower) SPI -mode. ESP32 and ESP32-S3 chips can access SD cards using either mode. SPI mode -makes use of a `SPI` host peripheral, which cannot concurrently be used for -something else. +mode. -The ``slot`` argument determines which mode is used. Different values are -available on different chips: - -====== ================= ============ ======================== -Slot Supported chips Mode Supported data width -====== ================= ============ ======================== -0 ESP32-S3 SD/MMC 1, 4, or 8 bits. -1 ESP32, ESP32-S3 SD/MMC 1 or 4 bits. -2 ESP32, ESP32-S3 `SPI` (id=1) 1 bit. -3 ESP32, ESP32-S3 `SPI` (id=0) 1 bit. -====== ================= ============ ======================== +SPI mode makes use of a `SPI` host peripheral, which cannot concurrently be used +for other SPI interactions. -.. note:: On the original ESP32, SDMMC slot 0 is unavailable as its pins are - used to communicate with on-board flash memory. +The ``slot`` argument determines which mode is used. Different values are +supported on different chips: + +========== ======== ======== ============ ============ +Chip Slot 0 Slot 1 Slot 2 Slot 3 +========== ======== ======== ============ ============ +ESP32 SD/MMC SPI (id=1) SPI (id=0) +ESP32-C3 SPI (id=0) +ESP32-C6 SPI (id=0) +ESP32-S2 SPI (id=1) SPI (id=0) +ESP32-S3 SD/MMC SD/MMC SPI (id=1) SPI (id=0) +========== ======== ======== ============ ============ + +Different slots support different data bus widths (number of data pins): + +========== ========== ===================== +Slot Type Supported data widths +========== ========== ===================== +0 SD/MMC 1, 4, 8 +1 SD/MMC 1, 4 +2 SPI 1 +3 SPI 1 +========== ========== ===================== .. note:: Most ESP32 modules that provide an SD card slot using the dedicated hardware only wire up 1 data pin, so the default @@ -105,8 +115,9 @@ Additional details depend on which ESP32 family chip is in use: Original ESP32 ~~~~~~~~~~~~~~ -Pin assignments in SD/MMC mode are fixed on the original ESP32. When accessing a -card in SPI mode, pins can be set to different values in the constructor. +In SD/MMC mode (slot 1), pin assignments in SD/MMC mode are fixed on the +original ESP32. The SPI mode slots (2 & 3) allow pins to be set to different +values in the constructor. The default pin assignments are as follows: @@ -177,6 +188,19 @@ parameters ``sck``, ``cs``, ``miso``, ``mosi`` as needed to assign pins. In either mode the ``cd`` and ``wp`` pins default to disabled, unless set in the constructor. +Other ESP32 chips +~~~~~~~~~~~~~~~~~ + +Other ESP32 family chips do not have hardware SD/MMC host controllers and can +only access SD cards in SPI mode. + +To access a card in SPI mode, set ``slot`` parameter value 2 or 3 and pass +parameters ``sck``, ``cs``, ``miso``, ``mosi`` to assign pins. + +.. note:: ESP32-C3 and ESP32-C6 only have one available `SPI` bus, so the only + valid ``slot`` parameter value is 2. Using this bus for the SD card + will prevent also using it for :class:`machine.SPI`. + cc3200 `````` |