CH378 is a file management control chip for fast reading and writing of files in U disk or SD card. CH378 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 and 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 compatibility) MMC card and TF card).
CH378 supports three communication interfaces: 8-bit parallel interface, SPI interface or asynchronous serial interface. The controller such as MCU/DSP/MPU can control the CH378 chip through any of the above communication interfaces, access the files in the U disk or SD card or Communicating with a computer.
The following figure shows the application block diagram of CH378.
- Supports 12Mbps full speed and 480Mbps high speed USB communication, 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;
- Support for control transfer, bulk transfer, and interrupt transfer of USB devices;
- Automatically detect the connection and disconnection of USB devices or SD cards, and provide event notification for device connection and disconnection;
- Provides up to 50MHz SPI host interface, supports SD card and MMC card and TF card compatible with its protocol, etc;
- Protocol processor with built-in USB control transfer to simplify common control transfers;
- Built-in firmware handles dedicated communication protocols for mass storage devices, supports USB storage devices with Bulk-Only transfer 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;
- Provide chip automatic presentation function, create and read presentation files;
- Provides high-speed 8-bit passive parallel interface to support parallel data bus connected to microcontroller;
- Provides SPI device interface up to 30MHz speed, supports SPI serial bus connected to microcontroller;
- Provide asynchronous serial port with speed up to 10Mbps, support serial interface connected to single chip microcomputer, support dynamic adjustment of communication baud rate;
- Support low power mode;
- Built-in 20KRAM, can be used as a file read/write buffer, or as a normal RAM, greatly reducing the resource requirements of external systems;
- Available in LQFP64M or LQFP128 lead-free package, compatible with RoHS.