四大高端RISC内核（国外英文资料）.docVIP

四大高端RISC内核（国外英文资料） The four high-end RISC cores This article comes from the Internet. You may find it hard to believe that, as we are still widely used today such as pork with latest dual-core or even CPU (Center Prosessing Unit central processing Unit), are based on the CISC instruction set was established in the 1960 s, it has been for more than 40 years. CISC is an abbreviation of Complex Instruction Set Computer in English, which means Complex Instruction Set. A large number of complex instruction, variable instruction length, a variety of ways of addressing is the characteristic of CISC, is also a CISC drawback: because these have greatly increased the difficulty of the decoding, and under the high speed hardware development of now, speed improvements brought by the complex instruction has already been inferior to waste some time on the decoding. In 1975, IBMs designer John Cocke studied IBM370 CISC system at that time, found 20% of the total number of instructions only simple instructions in the program calls accounted for 80%, and 80% of the number of instructions complex instruction is only a 20% chance of use. RISCs production, development and status quo The complexity is streamlined, and RISC is the abbreviation for Reduced Instruction Set Computer, which is the abbreviated Instruction Set Computer. Professor David Paterrso, the director of the RISC program at the university of California, Berkeley, named it in the 1970s and has been using it ever since. In the late 80s, the RISC structure gradually replaced the CISC (Complex Instruction Set Computing), a Complex Instruction Set Computing, and became the mainstream microprocessor design structure. The use of RISC technology is to optimize the command system, accelerate program compilation, and increase the speed of operation. The RISC technology USES a simpler and unified command format, fixed instruction length, and optimized addressing mode to make the overall computing structure more reasonable. In gen