Page 388 - DSP Integrated Circuits

8.6 Message-Based Architectures 373

Figure 8.18 Square mesh Figure 8.19 Boolean cubes

are controlled by the ith bit of the binary tag. The self-routing property of an MICN
avoids the need for a central controller, making it suitable for multiprocessors.
Figure 8.21 shows two interconnection networks of the tree type. In the binary
trees with N processors, a processor can be accessed in at most log2(AO time com-
pared to a one-dimensional array, O(N), and O( JN) for a rectangular array.
The number of processors available in a tree increases exponentially at each
level. If a problem being solved has this growth pattern, then tree geometry may
be suitable. FFTs are suitable for implementation using a massively parallel
approach with 2^ PEs arranged in a hypercube where N is the length of the
sequence.

Figure 8.20 An eight-port omega network. Input 3 is connected to output 5