Full speed USB device interface, compatible with USB V2.0, standard usb-a public design;Direct power connection from USB to PC Analog standard serial port, used to upgrade the serial peripheral, or add additional serial ports through USB;It supports 3.3V and 5V TTL target systems, and the serial port application is fully compatible with computers under Windows operating system, without modification; Support 5, 6, 7 or 8 data bits, support odd check, even check, blank symbol and no parity check; Support the transmission rate of serial port sending control signal and modem contact signal and serial port receiving ready signal;Plus level conversion module, supporting RS232, RS485 and other interfaces; (support module sold separately) Two parallel port interface modes: EPP Mode and MEM mode; USB to parallel port can be used for simple digital I / O control; Support various serial communication modes, UART, I2C, SPI, etc;Support 2-wire and 4-wire synchronous serial interfaces, and I2C supports 4 transmission speeds;Fully support STC MCU program download and debugging, STC official recommended program Support external output voltage, optional 3.3V / 5V or no output Support working status indication; Dual interface output; Hardware full duplex serial port, built-in transceiver buffer, supporting communication baud rate of 50bps ~ 2Mbps. Support Windows 98 / me / 2000 / XP / Server 2003 / Vista / Server 2008 / Windows 7 / 64 / 32 bits. Application: Analog standard serial port, used to upgrade the serial peripherals or add through USB. Where I2C, SPI, UART and TTL serial ports are required; Electronic engineer debugging and downloading; Debug various hardware systems and software systems; Serial port flashing Serial port expansion: emulates the standard serial port, used to upgrade the serial