Elastic buffers for digital rings

An elastic buffer to achieve end-to-end transmission synchronization of digital communication rings is proposed. The buffer must function as a first in first out (FIFO) store, though this does not necessarily mean that a standard FIFO chip should be used. When the ring is initialized, the buffer occupancy must be set up to give optimum accommodation. The buffer must be adequately sized to deal with worst-case timing conditions. However implemented, the control logic of the elastic buffer must include at least one synchronizer circuit and this must be arranged so that the probability of the output becoming anomalous is acceptably low. Variable packet-sizing makes for a relatively easy design of elastic buffer, while fixed sizing requires an additional synchronizer circuit and more buffer capacity, if an integral number of packets is to be circulated.