Patent ID: 7424022

Claim:
A method for providing a context datum associated with a source and/or destination device based on an address datum associated with said device, comprising the steps of: a) addressing, based on the address datum, a unit for providing an index, said unit containing, for each address datum, an indicator indicating whether the device is active; and b) addressing, based on the index provided by said unit, a context memory for providing the context datum associated with said device, wherein the context memory is capable of containing a number m of context data equal to a maximum number of system devices that can be active, and wherein the unit is capable of receiving a greater number n of address data, and the unit comprises a look up table composed of n bits distributed in an integral number of words of same size, each bit corresponding to an indicator having value 1 if said indicator indicates an active device and value 0 if not, a specific value being associated with each word, and the index associated with any indicator is determined on a basis of a sum of a number of bits equal to 1 between the bit corresponding to said indicator and the beginning of the word containing said bit and of the predetermined value associated with said word.