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doc(sdio_slave): add some information of slave protocol

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Michael (XIAO Xufeng) 2018-06-22 16:21:03 +08:00 committed by bot
parent 86d6c09387
commit fe076f5cb9
2 changed files with 24 additions and 8 deletions
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22
docs/en/api-reference/peripherals/esp_slave_protocol.rst
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@ -35,12 +35,28 @@ FIFO (sending and receiving)
0x090 - 0x1F7FF are reserved for FIFOs.
.. note:: This includes the CMD52 and CMD53 (block mode or byte mode).
The address of CMD53 is related to the length requested to read from/write to
the slave in a single transfer:
*requested length = 0x1F800-address*
The slave will respond with the length according to the length field in
CMD53, with the data longer than *requested length* filled with 0 (sending)
or discard (receiving).
.. note:: This includes both the block and the byte mode of CMD53.
The function number should be set to 1, OP Code should be set to 1 (for CMD53).
The slave will respond with the length according to the length field in CMD53 (1 of CMD52), with the data longer
than *requested length* filled with 0 (sending) or discard (receiving).
It is allowed to use CMD53 mode combination of block+byte to get higher
effeciency when accessing the FIFO by arbitrary length. E.g. The block
size is set to 512 by default, you can write/get 1031 bytes of data
to/from the FIFO by:
1. Send CMD53 in block mode, block count=2 (1024 bytes) to address
0x1F3F9=0x1F800-**1031**.
2. Then send CMD53 in byte mode, byte count=8 (or 7 if your controller
supports that) to address 0x1F7F9=0x1F800-**7**.
Interrupts
----------

10
docs/en/api-reference/peripherals/sdio_slave.rst
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@ -64,17 +64,17 @@ The SDIO slave driver uses the following terms:
- Sending: slave to host transfers.
- Receiving: host to slave transfers.
.. note:: Register names in ESP Rechnical Reference Manual are oriented from the point of view of the host, i.e. 'rx'
registers refer to sending, while 'tx' registers refer to receiving. We're not using `tx` or `rx` in the driver to
.. note:: Register names in ESP Rechnical Reference Manual are oriented from the point of view of the host, i.e. 'rx'
registers refer to sending, while 'tx' registers refer to receiving. We're not using `tx` or `rx` in the driver to
avoid ambiguities.
- FIFO: specific address in Function 1 that can be access by CMD53 to read/write large amount of data. The address is
related to the length requested to read from/write to the slave in a single transfer:
*requested length* = 0x1F800-address.
- Ownership: When the driver takes ownership of a buffer, it means the driver can randomly read/write the buffer
(mostly by the hardware). The application should not read/write the buffer until the ownership is returned to the
application. If the application reads from a buffer owned by a receiving driver, the data read can be random; if
the application writes to a buffer owned by a sending driver, the data sent may be corrupted.
(usually via DMA). The application should not read/write the buffer until the ownership is returned to the
application. If the application reads from a buffer owned by a receiving driver, the data read can be random; if
the application writes to a buffer owned by a sending driver, the data sent may be corrupted.
- Requested length: The length requested in one transfer determined by the FIFO address.
- Transfer length: The length requested in one transfer determined by the CMD53 byte/block count field.