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1、1/5/2015 9:57:20 PM,week05-5.ppt,1,Outline,Different Instruction Set Architectures - continued,1/5/2015 9:57:24 PM,week05-5.ppt,2,Intelligent Model for Computation,While the stored-program concept is an important one (which allows that the same hardware can be used to solve different problems by cha
2、nging the programs), however, we have to write different programs for different problems On the other hand, it is hard to imagine that we humans need to acquire a new program for each problem It seems a more attractive alternative is to allow the hardware to learn from examples and experience In thi
3、s case, we do not have to write programs for each different problem (we still need to develop learning algorithms),1/5/2015 9:57:25 PM,week05-5.ppt,3,Neural Networks,An attempt based on learning is implemented using neural networks A neural network is a network of neurons, which is defined as follow
4、s,1/5/2015 9:57:25 PM,week05-5.ppt,4,Biological Neurons,1/5/2015 9:57:25 PM,week05-5.ppt,5,Neural Networks are Turing Machine Equivalent,We can show that neural networks are equivalent to any computers in terms of computational capability,1/5/2015 9:57:25 PM,week05-5.ppt,6,Neural Networks are Turing
5、 Machine Equivalent,We can show that neural networks are equivalent to any computers in terms of computational capability,1/5/2015 9:57:26 PM,week05-5.ppt,7,Automatic Driving,1/5/2015 9:57:26 PM,week05-5.ppt,10,No Hands Across America,1/5/2015 9:57:26 PM,week05-5.ppt,11,No Hands Across America,12,AI
6、 Using Deep Networks,Google, Facebook, and Apple all hire many people in deep learning in the last few years Many of the recent improvements in natural language processing and speech recognition are due to deep learning Baidu, Chinese counterpart of Google, created a deep learning instruction Can yo
7、u guess how much will it invest?,13,AI Using Deep Networks,Google, Facebook, and Apple all hire many people in deep learning in the last few years Many of the recent improvements in natural language processing and speech recognition are due to deep learning Baidu, Chinese counterpart of Google, crea
8、ted a deep learning instruction Can you guess how much will it invest? $300 million.,1/5/2015 9:57:27 PM,week05-5.ppt,14,Instruction Set Architecture Examples,Appendix E gives a survey of different RISC architectures You can find a brief introduction to VAX at We will cover three more instruction se
9、t architectures Single instruction architecture Intel 80 x86 instruction set architecture ARMv7 (32-bits) and ARMv8 (64-bit) instruction set architectures,1/5/2015 9:57:27 PM,week05-5.ppt,15,Single Instruction Computers,We have learned the MIPS instruction set It includes arithmetic and logic instru
10、ctions, load and store instruction, and decision making instructions For a complete instruction set, at the minimum, it should include Some arithmetic and logic instructions Data transfer instructions Branching instructions At the minimum, how many different instructions do we have to have?,1/5/2015
11、 9:57:27 PM,week05-5.ppt,16,Single Instruction Computer (SIC),A single instruction computer has only one instruction There exist several different versions An elegant one has only the following type of instruction (Subtract-and-Branch-if-Negative) It implements,1/5/2015 9:57:27 PM,week05-5.ppt,17,SI
12、C Architecture,The SIC computer is as powerful as any other computers in terms of computational capability How can we show that?,1/5/2015 9:57:27 PM,week05-5.ppt,18,SIC Architecture,The SIC computer is as powerful as any other computers in terms of computational capability How can we show that? By s
13、howing that we can implement all the instructions in a computer using the SIC instruction only,1/5/2015 9:57:28 PM,week05-5.ppt,19,SIC Architecture,What does the following program do? Here .+1 means the address after the current one,1/5/2015 9:57:28 PM,week05-5.ppt,20,SIC Architecture,What does the
14、following program do? It copies a number from memory location a to memory location b,1/5/2015 9:57:28 PM,week05-5.ppt,21,SIC Architecture,How about this one?,1/5/2015 9:57:28 PM,week05-5.ppt,22,SIC Architecture,How about this one? Memory a = Memory a + Memory b,1/5/2015 9:57:28 PM,week05-5.ppt,23,SI
15、C Architecture,A more complicated one,1/5/2015 9:57:29 PM,week05-5.ppt,24,SIC Architecture,A more complicated one Memory c = Memory a * Memory b,1/5/2015 9:57:29 PM,week05-5.ppt,25,SIC Architecture,SIC computers would not be as fast as a typical computer? Why? On the other hand, SIC computers provide some distinctive advantages For example, since there is only one instruction, it can be implemented using only one type of logic (for example, half-adders), which can be critical for building chemical and optical computers,