1. A method of maintaining a global clock within a multiprocessor system having a plurality of nodes that are connected in a network via links, wherein the plurality of nodes includes a first node and a second node, the method comprising: mapping a virtual spanning tree onto the network; configuring the nodes and the links such that each node is in a parent-child relationship with one or more other nodes in the virtual spanning tree; generating a global clock in a root of the virtual spanning tree; and communicating global clock signals down the virtual spanning tree to each of the nodes.