Case 4

1.How does a CPU process data?

a) The control unit fetches (gets) the instruction from memory.

b) The control unit decodes the instruction (decides what it means) and directs that the necessary data be moved from memory to the arithmetic/logic unit. These first two steps together are called instruction time, or I-time.

c) The arithmetic/logic unit executes the arithmetic or logical instruction. That is, the ALU is given control and performs the actual operation on the data.

d) The arithmetic / logic unit stores the result of this operation in memory or in a register. Steps 3 and 4 together are called execution time, or E-time.

2. What is the very 1^st CPU? Who is its inventor?

In November, 1971, a company called Intel publicly introduced the world's first single chip microprocessor, the Intel 4004 (U.S. Patent #3,821,715), invented by Intel engineers Federico Faggin, Ted Hoff, and Stanley Mazor. After the invention of integrated circuits revolutionized computer design, the only place to go was down -- in size that is. The Intel 4004 chip took the integrated circuit down one step further by placing all the parts that made a computer think (i.e. central processing unit, memory, input and output controls) on one small chip. Programming intelligence into inanimate objects had now become possible.

3. What are the similarities and differences of a CPU and the Human Brain?

Similarities:

a) Both are used for storage of information, to process information and to run tasks.

b) Both play extremely important roles in society, comerce, entertainment and science

c) Both work by combining the processes of several components and parts to perform their tasks.

d) Both work by transmitting "logic signals" to each of their parts. Signals are both electrical

e) Both can change with time. (the brain evolves, while the computer upgrades with technological advances)

f) Both can increase their memory storage capacity

g) Both computers and brain have repair and "backup" systems.

h) Both can degrade. Computers break down and brain cells deteriorate

Differences:

a) Brains are analogue; computers are digital

b) The brain uses content-addressable memory

c) The brain is a massively parallel machine; computers are modular and serial

d) Processing speed is not fixed in the brain; there is no system clock

e) Short-term memory is not like RAM

f) No hardware/software distinction can be made with respect to the brain or mind

g) Synapses are far more complex than electrical logic gates

h) Unlike computers, processing and memory are performed by the same components in the brain

i) The brain is a self-organizing system

j) Brains have bodies

k) The brain is much, much bigger than any [current] computer

4. What is the importance of Registers in the CPU?

processor register is a small amount of storage available as part of a CPU or other digital processor. Such registers are (typically) addressed by other mechanisms than main memory and can be accessed more quickly. Almost all computers, load-store architecture or not, load data from a larger memory into registers where it is used for arithmetic, manipulated, or tested, by some machine instruction. Manipulated data is then often stored back in main memory, either by the same instruction or a subsequent one. Modern processors use either static RAM or dynamic RAM as main memory, the latter often being implicitly accessed via one or more cache-levels. A common property of computer programs is locality of reference: the same values are often accessed repeatedly and frequently used values held in registers improves performance. This is what makes fast registers (and caches) meaningful.

5. How does RAM stores data?

RAM stores the data in memory cells that are arranged in grids much like the cells are arranged in a spreadsheet, from which data, in the binary form of 1's and 0's, can be accessed and transferred at random to the processor for processing by the system's software.

6. Prove or disprove: It is possible to have a computer with no processor. Note: Do it scholarly.

It’s impossible not to have processor in a certain computer. The processor stands to be the brain of a certain computer. Without the processor the computer will not work. No one will do the process.

7. By the way, what was really the problem of the original Vonn Neuman Architecture? What is the significance of using digital computer rather than analog one?

It’s easy and accurate. One advantage of digital circuits when compared to analog circuits is ^[2] signals represented digitally can be transmitted without degradation due to noise. Computer-controlled digital systems can be controlled by software, allowing new functions to be added without changing hardware.

Thursday, June 30, 2011

Case 3

Give the correct Truth table for the following combined gates

1.

2.

*** random thougths @ 8:14 PM

case 2

Research at least three computer architecture models. Differentiate each with the Von Neumann Model.

The "von Neumann" machine & parallel processing

This architecture basically serves the Turing machine very well. The Turing machine is a bit more of a philosophical model, whereas the von Neumann architecture is a specification for the implementation of one. The CPU here is a serial processor unit which, in any way you put it, never executes more than one instruction at any given time, or per clock cycle. The CPU then has a couple of pins available that are connected to outside devices or buses. Sometimes the buses don't really contain anything, but you could put some PCI, PCIe, ISA or other kinds of electronics in them, or you could attach some device to a serial, parallel, USB or FireWire port and then the more advanced Operating Systems would allow the automatic registration of these devices and subsequent allocations of address spaces and such (through a driver and hardware-specific communication protocol like USB has).

The CPU is connected to the various other components of the computer by buses, which are a set of wires forming connections.

Even when the computer seems to be idle, lots is going on. Millions of interchanges are happening between the components, passing along a data highway called the bus. Various input/output controllers work with the CPU to ensure that all this traffic is regulated in an orderly way, so that the PC does not crash. The bus transports the data between the CPU and the other components. It is a ribbon connector, part of the motherboard. However we cannot look at the motherboard to point out the bus; it is a complex arrangement of circuits that are printed on top of and below the motherboard. These circuits are called traces.

Comparison of Harvard and Von Neumann Architectures

In Harvard architecture, the data bus and address bus are separate. Thus a greater flow of data is possible through the central processing unit, and of course, a greater speed of work. Separating a programme from data memory makes it further possible for instructions not to have to be 8-bit words. For example the Microchip PIC16F84 microcontroller uses 14 bits for instructions which allows for all instructions to be one word instructions. It is also typical for Harvard architecture to have fewer instructions than Von-Neumann's, and to have instructions usually executed in one cycle.

Microcontrollers with Harvard architecture are also called Reduced Instruction Set Computer (RISC) microcontrollers. Microprocessors with Von-Neumann's architecture are called Complex Instruction Set Computers (CISC).

*** random thougths @ 8:00 PM