Introduction to CH375 chip and its connection with 51 SCM __ch375

In MP3 this project, in addition to the decoding module, the most important is the U disk read and write module, we need to send music through the U disk to the microcontroller, and then output, and in this module we choose the CH375 this chip.

Similarly, because the project is still in the hardware circuit production phase, today can only briefly introduce some of its functions and its connection, the specific software read and write in detail later.

CH375 Introduction:

CH375 is a USB bus universal interface chip, support Usb-host host mode and Usb-device/slave device mode. On the local side, CH375 has 8-bit data bus and read, write, slice control line and interrupt output, can easily hook to the microcontroller/dsp/mcu/mpu and other controllers of the system bus. In the USB host mode, CH375 also provides serial communication mode, through serial input, serial output and interrupt output and SCM/dsp/mcu/mpu and other connected.

For CH375 in the USB device mode, the relevant information can refer to the CH372 manual. CH375 USB host way support commonly used USB full speed device, external SCM can communicate with USB device by CH375 according to the corresponding USB protocol. CH375 also has built-in firmware to deal with the special communication protocol for Mass-storage mass storage devices, and the external SCM can read and write commonly used USB storage devices (including USB hard disk/USB flash disk/u disk) directly in the sector as the basic unit.

The following is the mode diagram of CH375 and SCM connection:

In the practical application, the CH375 chip and the monolithic integrated circuit connection way has two kinds, respectively is the same port way and the serial port way

① and the way of the mouth

The TXD pin of the CH375 is grounded or directly grounded by the 1kω of the lower pulling resistance, so that the CH375 works at the same port and the RXD can be suspended.

CH375 chip has the common passive parallel interface, can connect a variety of SCM, DSP, MCU, etc. directly. In the typical application circuit of MCS-51 series Single-chip Microcomputer, the CH375 chip can be directly connected to the system bus of MCU-WR through the 8-bit passive parallel interface d7~d0,-RD,-cs, A0 and U2.

② Serial Port Mode

If the TXD pin of the CH375 chip is dangling or not grounded by a pull resistor, then the CH375 works in the serial port mode. In the serial mode, CH375 only need to connect with the Single-chip/DSP/MCU 3 signal lines, TXD pin, RXD pin and int# pin, other pins can be suspended. In addition to fewer connectors, the other peripheral circuits and the way the same port is basically the same

But the CH375 chip does not support serial communication mode