Patent ID: 7733857
Filing Date: 2010-06-08
Classification: H04L

Abstract:
1. A router for transferring data packets between external devices coupled to said router, said router comprising: a switch fabric; and R routing nodes coupled to said switch fabric, each of said R routing nodes capable of exchanging data packets with said external devices and with other ones of said R routing nodes via said switch fabric, wherein a first of said R routing nodes comprises: an inbound network processor comprising a first plurality of micro engines capable of forwarding incoming data packets from external ports to said switch fabric; an outbound network processor comprising a second plurality of micro engines forwarding outgoing data packets from said switch fabric to said external ports; and an asynchronous variables circuit for controlling access of said inbound and outbound network processors to at least one of i) a shared resource and ii) a shared variable in said router wherein said asynchronous variables circuit comprises a first register for storing a first data value associated with a first shared variable said control and status bits comprise a full flag and an empty flag indicating whether a state of said first data value in said first register is one of: i) uninitialized; ii) empty; iii) full, and iv) undefined, and said first data value may not be read in a protected mode when said full flag and empty flag indicate that said first data value is in an empty state.