FIFO memory system

This invention relates to a FIFO memory system (10) comprising a plurality of FIFO memories (20) for handling transmission queues in a serial digital communication system. The memory system comprises a plurality of blocks of memory (20a-c, 21a-e), each of the plurality of FIFO memories being assigned a block (20a) of the plurality of blocks of memory, the unassigned blocks of memory forming a block pool (21a-e). The memory system further comprises memory management means (LLT, PT) for adding at least one of the unassigned blocks of memory from the block pool to a FIFO memory on writing to the FIFO memory whereby the size of the FIFO memory is selectably variable, and for returning a block of memory from a FIFO memory to the block pool once the contents of the block of memory have been read.