ATM data controller

An ATM data controller for controlling data exchange between a data processing system and an ATM interface;

• the ATM data controller comprising:
• a first data buffer for buffering transmission data supplied from and received data to be supplied to the data processing system;
• a third data buffer for buffering transmission ATM cells to be transmitted to and received ATM cells received from the ATM interface;
• a second data buffer for buffering transmission cell data to be assembled into the transmission ATM cells and received cell data obtained by disassembling the received ATM cells;
• a data compressing/decompressing means for compressing the transmission data into the transmission cell data when the data compressing/decompressing means is controlled to compress the transmission data, controlling the second data buffer to buffer the transmission cell data supplied from the data compression/decompression means when the data compressing/decompressing means is controlled to compress the transmission data and to buffer the transmission data directly outputted from the first data buffer when the data compressing/decompressing means is not controlled to compress the transmission data, and decompressing the received cell data supplied from the second data buffer into the received data when the data compressing/decompressing means is controlled to decompress the received cell data;
• an ATM interface control section for assembling the transmission ATM cells by adding cell-headers onto the transmission cell data, in the cell-headers data-compression flags being set when the ATM interface control section is controlled to set the data-compression flags, disassembling the received ATM cells into the received cell data by deleting cell-headers from the received ATM cells, and controlling the second data buffer to output the received cell data towards the data compressing/decompressing means when the data-compression flags are set in the cell-headers of the received ATM cells and to output the received cell data towards the first data buffer when the data-compression flags are not set in the cell-headers;
• and
• a control section for controlling the data compressing/decompressing means to compress the transmission data and the ATM interface control section to set the data-compression flags, when the transmission data is to be compressed.