.. _msc_host:

MSC Host
================

Overview
--------

This example project shows USB MSC Host

Board Setting
-------------

- Connect a USB port on PC to the PWR DEBUG port on the development board with a USB Type-C cable

- Connect a USB port on the development board USB0 to a USB flash disk(Attention: The `Format Type` support FAT, FAT32 or exFAT) with a USB Type-C convert Type-A cable

  .. image:: ../../../../../../samples/cherryusb/doc/UDisk_Format.png
     :alt: UDisk_Format

Software Setting
-----------------------

- In the CMakeLists.txt file, if sdk_compile_definitions(-DFATFS_ONLY_NONCACHEABLE_BUF=1) is commented, FATFS supports data transfer by using cacheable buffer. If sdk_compile_definitions(-DFATFS_ONLY_NONCACHEABLE_BUF=1) is uncommented, FATFS only supports data transfer by using noncacheable buffer.
- When sdk_compile_definitions(-DFATFS_ONLY_NONCACHEABLE_BUF=1) is commented, it is recommended to align cache line size for the buffer address, otherwise it will affect transmission performance.

Running the example
-------------------

- Download the program to the development board to run, and use the serial port debugging assistant to view the output log

- First, a "cherryusb _msc_test.txt" file will be created in the USB flash drive, and the string "cherryusb fatfs demo..." will be written into the file, with a total of 100 lines or 2500 bytes; Then read out the data of the file, with a total length of 2500.

- Secondly, it will scan the directories and files under the root directory of the USB drive and print out the directory name and file name.

Example of output log
---------------------

- When the USB port0 of the development board is connected with a USB flash disk, the serial port debugging assistant will display the following data:


.. code-block:: console

   FATFS cherryusb mount succeeded!
   test fatfs write
   write success, write len：2500
   test fatfs read
   read success, read len：2500

   Direcotry Path: /
   Folder Name: LOST.DIR
   Folder Name: DCIM
   Folder Name: MIUI
   Folder Name: Android
   Folder Name: tencent
   File   Name: USBHost.txt
   File   Name: cherryusb_msc_test.txt