This algorithm uses the turn model proposed by Glass and Ni. Virtual channels can be used to avoid deadlocks, but the implementation of virtual channels requires additional logic gates and hardware circuitry. Some packets in the network are then blocked and will stay blocked forever due to these deadlocks. Re-routing packets around faulty components may form cycle in the network leading to deadlocks. InputĜXDXĜX>DXĜX=DXĜX=DXĜY =DyĜY =dyĬoreĞSNW NEWS WSEN WNSE SEWN NWESĞSNW WNSE Output directions in different destination quadrants (N: North, E: East, S: South, W: West) However, the delivery of the packet is always guaranteed if there is an existing path to the destination. The worst case, the packet takes the third output direction which obviously leads to the longest path. In this case, the packet may take a slightly longer path. Otherwise, if the router finds any link faulty, the packet will be routed in an alternative direction. The packet traversal path to destination through these directions is minimum, when all links in the path are fault free. Paths in those two output directions leading towards destination are checked first. Configuration for the situation: (a) with zero fault (b) with faulty pathsįrom any node in 2-D mesh, packets generally have two output directions leading towards destination and one output direction going away from destination. Turn model: Turns taken in different destination quadrants for both clockwise and anticlockwise directionsįig. IEtelei № Calunm 2 ill J ni 11 id Tuljle J farĪlgorithm 2: Pseudocodes of the proposed fault tolerance routingįig.
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