| 摘要 |
PURPOSE: A WAN(Wide Area Network) interface device in a DSLAM(Digital Subscriber Line Access Multiplexer) system is provided to embody a WAN interface board using a cell bus interface block which performs an ATM(Asynchronous Transfer Mode) based data transmission function, a traffic management function, and a UPC(Usage Parameter Control) function, and an OAM(Operation, Administration, and Maintenance) function. CONSTITUTION: An SDRAM(Synchronous Dynamic RAM)(100) stores an application program code by a block unit. A flash memory(200) stores a booting program code by the block unit. A CPU(300) is booted by the booting program stored in the flash memory(200) when a power is turned on, and reads the application program of an SDRAM(100) and performs various control operations. An EEPROM(Electrically Erasable/Programmable ROM)(400) stores the booting program code by the block unit. An SSRAM(Single Static RAM)(500) temporarily stores ATM cells, and stores routing information of the ATM cells. A cell bus interface unit(600) receives line side and network side firmwares from the CPU(300) through a dual port RAM communication, and performs self management functions such as a traffic management function, a UPC function, and an OAM function. A UNI(User Network Interface)(700) receives the ATM cell from the cell bus interface unit(600), transmits the received ATM cell to a WAN. The UNI(700) receives an ATM cell from the WAN, and outputs the received ATM cell to the cell bus interface unit(600). An EPLD(Electrically Programmable Logic Device)(800) generates a control signal under the control of the CPU(300). The EPLD(800) receives separate board states from the cell bus interface unit(600) and the UNI(700), and notifies the separate board states to the CPU(300). A clock providing unit(900) provides various clocks to the cell bus interface unit(600) and the UNI(700).
|
