CPU: Past, Present, “A CPU (central processing unit) is the “brain” of the computer; it follows the instructions of the software to manipulate data into information. ” (Sawyer, 2010, p. 208) The CPU performs logic and arithmetic operations, controls instruction processing, and supervises the overall operation of the computer. The main components of the CPU are the CU (control unit) and the ALU (arithmetic/logic unit). (Dugger & Gerrish, 1994, p. 78) The CPU also has registers which temporary store data during processing, and buses that act as roadways which transmit bits of data within the CPU and to other components on the motherboard. CPU: The control unit deciphers the instructions from the input and moves them into memory. For each instruction the CPU will fetch the instruction, decode the instruction, execute the instruction, and store the result. These four basic operations are known as a machine cycle. The control unit is therefore responsible in the CPU to instruct and control where the data goes to and what will happen to it. (Sawyer, 2010, p. 208)
ALU: The arithmetic/logic unit executes data that the control unit has sent to it. It performs basic arithmetic operations such as addition, subtraction, multiplication, and division. The ALU also performs basic logic operations such as comparing two numbers to see if they are equal, less than, greater than, or not equal. (Dugger & Gerrish, 1994, p. 581) Registers: “Registers are high-speed storage areas that temporarily store data during processing. ” (Sawyer, 2010, p. 209) The CPU contains several types of registers such as an instruction register, address register, storage register, and an accumulator register.
These registers may store a program instruction, store data while being processed, or store the results of a calculation. Without the registers the control unit or arithmetic/logic unit could not complete their work. Buses: “A bus is a group of parallel conductors which carry information. ” (“Microprocessors,” 1983, pp. 2-2) The conductors may be wires in a cable, foil patterns on a printed circuit board, or microscopic metal deposits in a silicon chip. Buses act as data roadways to get data from one place to another as needed. The term CPU/central processing unit has been in use since the 1960s.
Nowadays, we are more familiar with the term microprocessors which are CPUs that are manufactured on integrated circuits in a single-chip package. However, before getting into today’s technology I will take a look at the past CPU technology. Past Exactly which computer was the first electronic computer completed in the United States is a controversial subject. Iowa State University claims that the Atanasoff-Berry Computer at ISU was completed in 1942 just before its creator was called up for duty in the war effort. (Munns) Another computer at the University of Pennsylvania which was funded by the military was completed in 1946 by J.
Presper Eckert and John Mauchly. First Generation: Eckert and Mauchly’s invention was called the Electronic Numerical Integrator and Calculator, or as many now know it, as ENIAC. This first generation computer weighed 30 tons and contained 18,000 vacuum tubes. ENIAC could do 5000 additions per second. Each specific sequence of calculations had to be hard-wired into the machine. To change programs, ENIAC had to be completely rewired. ENIAC is generally known as the first electronic computer in the United States. However, since ENIAC could not store a program it did not have, what we would call, a CPU. Dugger & Gerrish, 1994, p. 571) In 1945 John von Neumann created a design for a computer system. His design included four basic units for a computer: a CPU, an input device, an output device, and storage. (Dugger & Gerrish, 1994, p. 571) In 1946 John von Neumann joined with Eckert and Mauchly at the University of Pennsylvania to create the Electronic Discrete Variable Automatic Computer (EDVAC). EDVAC was completed in 1949. It contained almost 6000 vacuum tubes and had 12,000 diodes. EDVAC covered 490 square feet of flooring and weighed almost 9 tons. It required thirty people to operate it.
EDVAC is considered the first truly programmable electronic computer that included a central processing unit. No doubt the CPU was enormous, but still a recognizable CPU. (“EDVAC”) Second Generation: In 1954 Texas Instruments introduced the silicon transistor. This revolutionized computer technology and created the Second Generation of computers. Transistorized CPUs of the 1950’s and 60’s were no longer hampered by vacuum tubes and electrical relay. Second Generation computers were smaller, faster, more rugged, and more reliable. “With this improvement, more complex and reliable CPUs were built onto one or several rinted circuit boards containing discrete transistor components. ” (“Central Processing Unit”) Third Generation: The development of integrated circuits and their use in computers began in the mid 1960’s. This shift in technology brought about the Third Generation of computers which were faster, more reliable, cheaper to operate and much smaller. Throughout the advances in computer technology and electronics the CPU continued to become faster and smaller. Fourth Generation: In the early 1970’s, Ted Hoff at Intel invented the first microprocessor.
Essentially, this was the first time that a complete processing unit was contained within a single chip and it revolutionized the way computers were applied and designed forever. This is where the Fourth Generation of computers was born. The Intel 4004 was a four bit device, measured 1/8 inch by 1/6 inch, and could execute 60,000 operations per second. (Dugger & Gerrish, 1994, p. 574) By 1972 Intel had come out with an 8-bit microprocessor, the Intel 8008, and within a year had bettered it with the Intel 8080 which could execute about 290,000 operations per second.
In 1979, Motorola developed a 16-bit microprocessor. The Motorola 68000 was very popular in the blossoming personal computer market. Around the same time Intel rolled out their 16-bit microprocessor; the Intel 8086. While other companies tried to compete in the microprocessor market, it was generally Intel and Motorola who were in the race to built smaller and better processors with each other. By the mid 80’s each had produced 32-bit microprocessors. Beyond: According to Moore’s Law, at our rate of technological development, the complexity of an integrated circuit will double in about 24 months.
By the early 90’s, 64-bit microprocessors entered the market. Each succeeding processor is smaller and can produce data much faster. The 90’ saw Intel introduce its first Pentium chip and Motorola introduced their Power PC CPU. Throughout the 90’s Intel improved on its Pentium technology releashing the Pentium Pro, Pentium II, Pentium MMX, and Pentium III. In the late 90’s AMD introduced their Athlon CPU. The Athlon worked at 800 MHz. In 2000, both Intel and AMD released 1 GHz microprocessors in the Pentium 4 and Athlon CPU. By 2002, Intel’s Pentium 4 reaches 3. 06 GHz.
By 2006, both Intel and AMD introduce dual-core processors. 64-bit processors have been around for use in mainframes and supercomputers, but now 64-bit processors are being made for personal computers. Present Today’s main competitors for CPU’s in microprocessors are Intel and AMD. Motorola sold off their semiconductor manufacturing section to become Freescale, and has basically bowed out of the CPU race. CPU’s of today are extremely fast. The new Intel Core i7-980X Processor Extreme Edition released the beginning of 2010 has six cores, 12 threads, a max turbo speed of 3. GHz , a 12 MB Smart Cache, and a clock speed of 3. 33 GHz. (“Intel Processors,”) “The faster a CPU runs the more power it consumes and the more waste heat it produces. ” (Sawyer, 2010, p. 206) For that reason, rather than increasing clock speed, Intel and AMD have pursued using multi-core technology, which employs additional CPU cores and runs them in parallel. Dual, Quad, and multi-core processors are very popular today in CPUs for computers, games and other technology that needs a CPU. Future 128-bit microprocessors are still being developed. Some experts predict that advances in microprocessor technology will produce a 50 GHz processor by 2010, the kind of power that will be required to support such function as true speech interfaces and real-time speech translation” (Sawyer, p. 206) ClusterOnaChip (CoC) is a popular example of the future in CPU technology. Engineers are working on how to place thousands of more processors in a “cluster” on a single chip. IBM in collaboration with the Georgia Institute of Technology has created a prototype silicon-germanium hetero-junction bipolar transistor able to operate at a speed of 500 GHz at 4. degrees Kelvin. At room temperature, the transistor achieves a speed of 350 GHz. “This demonstrates that speeds of half a trillion cycles per second can be achieved in a commercial, silicon-based technology, using large wafers and low-cost, silicon-compatible manufacturing techniques,” says John D. Cressler, Byers Professor at Georgia Tech’s School of Electrical and Computer Engineering and a researcher at the Georgia Electronic Design Center at Georgia Tech. Our current technological knowledge is not good enough to produce the microprocessors and CPU’s of the future.
We are limited by our current materials and in need of innovation to jump start us towards even smaller and faster CPU’s. One can only dream of the day when rather than having a bulky transistor made of silicon, we have processors that are scaled down to the size of an electron itself. Conclusion With Moore’s Law in mind, we can see that over the past decades we have certainly obeyed his law. From ENIAC to EDVAC, to transistors, to integrated circuits and single chip microprocessors, CPU technology has evolved and is still evolving to bring us the computers that e want and need. Further advances into CPU technology will allow us to compute faster and realize scientific discoveries that can change our world for the better. Our thirst for deep space exploration could become a reality. Medical research will be simplified. The possibilities are endless. References (1983). Microcomputer Basics. In Microprocessors (pp. 2-2). Benton Harbor, MI: Heath Company. Central Processing Unit. (n. d. ). Retrieved from http://www. spiritus-temporis. com/central-processing-unit/history. html Dugger, W. E. , & Gerrish, H.
H. (1994). Electronics Technology: Devices and Circuits. South Holland, IL: Goodheart-Wilcox Company, Inc. EDVAC. (n. d. ). Retrieved from http://www. spiritus-temporis. com/edvac/ Intel Processors. (n. d. ). Retrieved from http://www. intel. com/products/processor_number/about. htm Munns, R. (n. d. ). First-Computer controversy finally nearing a conclusion. Retrieved from http://www. scl. ameslab. gov/abc/articles/first-computer. html Sawyer, W. (2010). Hardware: The CPU & Storage. In Using Information Technology. New York, NY: McGraw-Hill.