Monday, August 27, 2007

EXERCISE 2




































memory chips- is non-volatile computer memory that can be electrically erased and reprogrammed. It is a technology that is primarily used in memory cards, USB flash drives (thumb drives, handy drive, memory stick, flash stick, jump drive), which are used for general storage and transfer of data between computers and other digital products. It is a specific type of EEPROM that is erased and programmed in large blocks; in early flash the entire chip had to be erased at once. Flash memory costs far less than byte-programmable EEPROM and therefore has become the dominant technology wherever a significant amount of non-volatile, solid-state storage is needed. Examples of applications include PDAs and laptop computers, digital audio players, digital cameras and mobile phones. It has also gained some popularity in the game console market, where it is often used instead of EEPROMs or battery-powered static RAM (SRAM) for game save data.







RAM CHIP-Random acces





mory (usually known by its acronym, RAM) is a type of data storage used in computers. It takes the form of integrated circuits that allow the stored data to be accessed in any order — that is, at random and without the physical movement of the storage medium or a physical reading head.
The word "random" refers to the fact that any piece of data can be returned in a constant time, regardless of its physical location and whether or not it is related to the previous piece of data.
[1] This contrasts with storage mechanisms such as tapes, magnetic discs and optical discs
, which rely on the physical movement of the recording medium or a reading head. In these devices, the movement takes longer than the data transfer, and the retrieval time varies depending on the physical location of the next item.








ROM CHIPS- is a computer file which contains a copy of the data from a read-only memory chip, often from a video game cartridge, a computer's firmware, or from an arcade game's main board. The term is frequently used in the context of emulation, whereby older games or computer firmware are copied to ROM files on modern computers and can, using a piece of software known as an emulator, be run on the newer computer.
ROM images are also used when developing for
embedded computers. Software which is being developed for embedded computers is often written to ROM files for testing on a standard computer before it is written to a ROM chip for use in the embedded system. At present, this article deals mainly with the use of ROM
in relation to emulation.




PROM- is a removable memory chip located within an ECM. PROM stands for
Programmable Read Only Memory. This memory chip contains the vehicle
characteristic information, as well as memory tables for such functions as spark timing,
fuel control, emission control strategy, etc. The information contained within the PROM
memory chip can be thought of as an instruction manual written for the ECM. Without
the proper PROM chip, an ECM may not function as intended for a specific vehicle
application. Also, if certainAn.








EPROM CHIPS-, or erasable programmable read-only memory, is a type of computer memory chip that retains its data when its power supply is switched off. In other words, it is non-volatile. It is an array of floating-gate transistors individually programmed by an electronic device that supplies higher voltages than those normally used in electronic circuits. Once programmed, an EPROM can be erased only by exposing it to strong ultraviolet light. That UV light usually has a wavelength of 235nm (for optimum erasure time) and belongs to the UVC range of UV light. EPROMs are easily recognizable by the transparent fused quartz window in the top of the package, through which the silicon chip can be seen, and which permits UV light during erasing.












EEPROM CHIPS-A simple program was written in assembly to blink a LED connected to port D, pin 2 (PD2) to
demonstrate the procedure to modify assembly programs for loading to off-chip EEPROM. The program
was designed such that the state of PD2 is toggled whenever an output compare 2 interrupt occurs. The
assembly program along with comments is listed below.




SEIAL PORTS- is a serial communication physical interface through which information transfers in or out one bit at a time (contrast parallel port). Throughout most of the history of personal computers, data transfer through serial ports connected the computer to devices such as terminals or modems. Mice, keyboards, and other peripheral devices also connected in this way.
While such interfaces as
Ethernet, FireWire, and USB all send data as a serial stream, the term "serial port" usually identifies hardware more or less compliant to the RS-232 standard, intended to interface with a modem or with a similar communication device.
For many computer peripheral devices the
USB interface has replaced the serial port — as of 2007, most modern computers are connected to devices through a USB connection, and often don't even have a serial port. The serial port is omitted for cost savings, and is considered to be a legacy port. However serial ports can still be found in industrial automation systems and some industrial and consumer products. Network equipment (such as routers and switches) often have serial ports for configuration. Serial ports are still used in these areas as they are simple, cheap and allow interoperability between devices. The disadvantage is that setting up serial connections may require expert knowledge and complex.






Universal Serial Bus- an external bus standard that supports data transfer rates of 12 Mbps. A single USB port can be used to connect up to 127 peripheral devices, such as mice, modems, and keyboards. USB also supports Plug-and-Play installation and hot plugging








BUSES-is a large road vehicle designed to carry numerous passengers in addition to the driver and sometimes a conductor. The name is a neologic version of the Latin omnibus, which means "for everyone


LOCAL BUSES-VESA Local Bus is an example of a local bus design.
Although VL-Bus was later succeeded by
AGP, it is not correct to categorize AGP as a local bus. Whereas VL-Bus operated on the CPU's memory bus at the CPU's clock speed, an AGP peripheral runs at specified clock speeds that run independently of the CPU cla computer bus that connects directly, or almost directly, from the CPU to oneis or more slots on the expansion bus. The significance of direct connection to the CPU is avoiding the bottleneck created by the expansion bus, thus providing fast throughput.
ock (usually using a divider of the CPU clock).