Dual ethernet controller and packet transmitting method between two ethernet controllers

摘要

PURPOSE: Dual Ethernet controller and a method for transmitting packets between two Ethernet controllers are provided to minimize a chip size and fabricate it at a low cost by switching packets with a minimum buffer size. CONSTITUTION: Output data of the second Ethernet controller(20) connected with a LAN(Local Area Network) is inputted to a data bus(50) and to the second buffer(40b), and an output of the data bus(50) and an output of the second buffer(40b) are multiplexed and then inputted to the first Ethernet controller(10) connected with a WAN(Wide Area Network). Output data of the first Ethernet controller(10) is inputted to the data bus(50) and the first buffer(40a), and the output of the data bus(50) and an output of the first buffer(40a) are multiplexed and then inputted to the second Ethernet controller(20). A dummy packet, which has been generated as an output signal(WAN carrier sensing) of the second Ethernet controller(20) was inputted to the second dummy packet generator(70b), is inputted to the first Ethernet controller(10), and a dummy packet, which has been generated as an output signal(LAN carrier sensing) of the first Ethernet controller(10) was inputted to the first dummy packet generator(70a), is inputted to the second Ethernet controller(20).