Von Neuman Architecture has been used in normal contollers, while Harvard architecture has been used in DSPs. The features of the latter is as follows:
1. Instruction and Data Memory are separated.
2. More complex internal data bus structures, so as to make data flow smoothly, which is required especially due to the nature of DSP algorithms.
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3. MAC (Multiply And Accumulate) Instructions are provided and this MAC operations are executed efficiently.
4. Some ALU instructions are also to be provided so as to treat data width extension.
DSPs are much more powerful and complex processors than microcontrollers. They have very complex instructions with multi-pipelined architectures to enable them to perform enormous amounts of computations..
So if i'm not mistake main differenc that is microcontroller use simplest commands to execute some actions, which was writen in ROM, so microcontroller works in program level. buy DSP works in hardware levle, using cells interconection to execute some commands.
DSP is used for signal processing, so it's a mathemetic intensive processor.
Microcontroller is used for controll the information flow through the input output port, so it's a information transfer intensive processor.
So if i'm not mistake main differenc that is microcontroller use simplest commands to execute some actions, which was writen in ROM, so microcontroller works in program level. buy DSP works in hardware levle, using cells interconection to execute some commands.