说明：  CH374是一个USB总线的通用接口芯片，支持USB-HOST主机方式和USB-DEVICE/SLAVE设备方式，内置3端口HUB根集线器，支持低速和全速的控制传输、批量传输、中断传输以及同步/等时传输。在本地端，CH374具有8位数据总线和读、写、片选控制线以及中断输出，可以方便地挂接到单片机/DSP/MCU/MPU等控制器的系统总线上。除此之外，CH374还提供了节约I/O引脚的SPI串行通讯方式，通过3线或者4线SPI串行接口以及中断输出与单片机/DSP/MCU/MPU等相连接。
(CH374 is a universal interface chip for USB bus, supports USB-HOST host mode and USB-DEVICE / SLAVE device mode, built-in 3-port HUB root hub, supports low-speed and full-speed control transmission, batch transmission, interrupt transmission, and synchronization / isochronous transmission. At the local end, CH374 has an 8-bit data bus and read, write, chip select control lines, and interrupt output, which can be easily connected to the system bus of a microcontroller / DSP / MCU / MPU controller. In addition, CH374 also provides a SPI serial communication method that saves I / O pins. It is connected to a single-chip computer / DSP / MCU / MPU through a 3- or 4-wire SPI serial interface and interrupt output.)