Apparatus with expansibility for processing atm layer function

The present invention for the cell start and cell input data extracted by using the input signal read receive a cell transfer can signal cell in the clock on the subscriber side physical layer relates to the ATM layer function processing unit for processing the ATM protocol in ATM cell units buffer storage extracts a flag according to the stored cell number, and receiving ATM cell layer by using the interrupt flags and the extracted perform a multiplexing operation according to the scheduling algorithm dyulring cell processing means (10); Micro-processor to form a cell from the transmission data from generates, and stores in the buffer the cell at the same time interrupts, the processor interface means for receiving control a multiplexer and passes the state (30); When the output cell buffer and a connection table for connecting the cell buffer and the counter is output to store a cell arriving, to look-up a connection table, that route value match signal output from the connection table of the input cell according to the value of the output counter identifier performing cell routing and, ATM layer sends the cell that is responsible for the network side routing the output cell to a physical layer function processing unit 50, a broadcasting and selectively broadcasts connected to each of the physical link based on a field allocated in the appropriate output window identifier value processing means (20); And said ATM layer reception cell processing section 10 and the ATM layer sends the cell processing means 20 wherein the ATM layer reception cell processing means 10 in response to the control signal processor intepeyiseu means (30) between the ATM layer sends the cell processing in a cell which is input to a means (20) the network side and the subscriber side physical layer function processing function mode processing means operative can access to the 50, 40 connected to each physical link independently of the cell by cell virtual channel / deriving the required information for each virtual path, and there is an effect of the expansion function and size possible by simply connecting the present invention is physically implemented in accordance with the size of the location and function of the system by using this process, and using the ATM protocol.