U disk and SD card file management control chip CH376


CH376 is a file management control chip for reading and writing files in a USB flash drive or SD card.

CH376 supports USB device mode and USB host mode, and has built-in basic firmware of USB communication protocol, built-in firmware for processing the dedicated communication protocol of Mass-Storage mass storage device, built-in communication interface firmware of SD card, built-in FAT16, FAT32 and FAT12 file system management firmware, support common USB storage devices (including U disk / USB hard disk / USB flash disk / USB card reader) and SD card (including standard capacity SD card and high capacity HC-SD card and protocol compatible MMC card and TF card).

CH376 supports three communication interfaces: 8-bit parallel port, SPI interface or asynchronous serial port. The controller such as MCU/DSP/MPU can control CH376 chip through any of the above communication interfaces, access files in U disk or SD card or Communicating with a computer. The USB device mode of the CH376 is fully compatible with the CH372 chip. The USB host mode of the CH376 is basically compatible with the CH375 chip.

The following figure shows the application block diagram of CH376.


  • Support 1.5Mbps low speed and 12Mbps full speed USB communication, compatible with USB V2.0, peripheral components only need crystal and capacitor;
  • Support USB-HOST host interface and USB-DEVICE device interface, support dynamic switching host mode and device mode;
  • Supports control transfer, bulk transfer, and interrupt transfer of USB devices;
  • Automatically detect connection and disconnection of USB devices, provide event notification for device connection and disconnection;
  • Provide 6MHz SPI host interface, support SD card and MMC card and TF card compatible with its protocol;
  • A built-in USB control transfer protocol processor that simplifies common control transfers;
  • Built-in firmware handles dedicated communication protocols for mass storage devices, supports USB storage devices with Bulk-Only transport protocol and SCSI, UFI, RBC or equivalent command set (including USB flash drive / USB hard drive / USB flash drive / USB card reader);
  • Built-in FAT16 and FAT32 and FAT12 file system management firmware, support U disk and SD card with capacity up to 32GB;
  • Provide file management functions: open, create or delete files, enumerate and search files, create subdirectories, support long file names;
  • Provide file read and write functions: read and write files in multi-level subdirectories in units of bytes or in sectors;
  • Provide disk management functions: initialize disk, query physical capacity, query remaining space, read and write physical sectors;
  • Provides 2MB speed 8-bit passive parallel interface to support parallel data bus connected to single chip microcomputer;
  • Provides 2MB/24MHz speed SPI device interface, supports SPI serial bus connected to single chip microcomputer;
  • Provides asynchronous serial port up to 3Mbps speed, supports serial interface connected to single chip microcomputer, supports dynamic adjustment of communication baud rate;
  • Supports 5V supply voltage and 3.3V supply voltage as well as 3V supply voltage, support low power mode;
  • The USB device mode is fully compatible with the CH372 chip; the USB host mode is basically compatible with the CH375 chip;
  • Available in SOP-28 and SSOP20 lead-free packages, compatible with RoHS, SOP28 to DIP28 conversion board are provided, SOP28 package is compatible with CH375 chips.

relation files

file name file content
CH374DS1.PDF CH374 datasheet. CH374 is a USB-HOST&DEVICE general interface chip. It supports USB host and USB device, supports 12M USB full-speed communication and 1.5M low-speed communication, supports 8-bit parallel interface or SPI interface, supports all types of USB transmission and Hub operation, etc.
CH372DS1.PDF CH372/CH375/CH376 (device mode) datasheet. Easy-to-use USB-DEVICE general interface chip, used for users to quickly develop USB products. This datasheet introduces the basic transfer commands of USB devices.
CH376DS2.PDF CH376 datasheet (Ⅱ). Easy-to-use USB flash disk and SD card file management chip, supports host-slave USB applications, supports FAT32/FAT16/FAT12, supports SPI/8-bit parallel port/asynchronous serial port. MCU resource occupies less memory. This datasheet introduces USB basic transfer commands and external firmware in device mode.