Luigi Licciardi

A multichip module solution for high performance ATM switching

the high industrial importance that ATM (asynchronous transfer mode) is assuming in the telecommunication environment strongly drives technology improvements. A MCM-C 16/spl times/16 Switching Element (MCM-BASE16) for the industrial ATM cross connect UTXC is presented; implementation details are described regarding both the substate characteristics and the new IBM CCGA (ceramic column grid array) packaging technique. Electrical and thermal analysis results are reported and finally the testing methodology is presented both at the substrate and at the module level. The MCM-BASEI6 has a global throughput of 5 Gbit/s, works at 77.8 MHz and dissipates approximately 10 W at the operating frequency; these results confirm the effectiveness of this new packaging technique in obtaining high speed and area performance.

An ATM Switching Element with programmable capacity

The paper presents a high performance A TM Switching Element with programmable switching capacity from 8 x 8 to 32 x 32 links, each at 311 Mbit/s. The 8 x 8 component is a single fully CMOS IC, the others can be obtained by properly connecting the 8 x 8 basic elements in Multichip Modules. It is shown how to connect them in order to avoid blocking problems, to increase the shared buffer availability and to improve the global system capacity of a factor of 2 or 4. The expanded Switching Element is a single component in terms of functionality and represents a single-stage in the ATM Switching Fabric. A MCM 16 x 16 Switch is also described and its features are presented. Both the components find an industrial application in the Italtel Cross Connect UTXC, which, using these elements, can provide systems from 5 up to 160 Gbit/s.