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 and automatic mission rate control, compatible with TL16C550C Supports serial port frame error