Figure 17.2 illustrates the general organization of the taxonomy of Figure 17.1.
Figure 17.2a shows the structure of an SISD.There is some sort of control unit (CU)
that provides an instruction stream (IS) to a processing unit (PU). The processing
unit operates on a single data stream (DS) from a memory unit (MU). With an
SIMD, there is still a single control unit, now feeding a single instruction stream to
multiple PUs. Each PU may have its own dedicated memory (illustrated in Figure
17.2b), or there may be a shared memory. Finally, with the MIMD, there are multiple
control units, each feeding a separate instruction stream to its own PU. The MIMD