CH384 is a four-port serial port and printing port chip for the PCI-Express bus. It includes four asynchronous serial ports compatible with 16C550 or 16C750 and an EPP/ECP enhanced bidirectional parallel port. It can also be expanded by adding a CH438 chip to up to 24 serial ports. The asynchronous serial port provides an independent 256-byte FIFO buffer for sending and receiving, supports IrDA infrared codec, supports 8Mbps communication baud rate, and can be used for RS232 serial port expansion of the PCI-E bus, PCIE high-speed serial port with automatic hardware rate control, and serial port Networking, RS485 communication, IrDA communication, parallel port/printing port expansion, etc. The same chip can be configured as a four-channel serial port + parallel port/printing port or a four-channel serial port + extended multi-serial port of the PCI-E bus. Provides a two-wire serial host interface, which can be connected to a serial EEPROM device similar to 24C0X for storing non-volatile data. The device identification (Vendor ID, Device ID, Class Code, etc.) of the PCIE board can be set in the EEPROM device. 3.3V power supply voltage, main I/O pins support 5V withstand voltage, and support serial port low-power sleep mode. Serial port: 4 completely independent asynchronous serial ports, compatible with 16C550,16C552,16C554 and 16C750 and enhanced Supports 5, 6, 7 or 8 data bits and 1 or 2 stop bits Supports odd, even, no check, blank 0, flag 1 and other check modes Programmable communication baud rate, supports communication baud rate of 115200bps and up to 8Mbps Built-in 256-byte FIFO first-in-first-out buffer, supporting 4 FIFO trigger levels Supports MODEM modem signals CTS,DSR,RI,DCD,DTR,RTS,and can be converted to RS232 level Supports hardware flow control signals CTS and RTS automatic handshake an