Found 826 Articles for Network

Handshaking is an I/O control approach to synchronize I/O devices with the microprocessor. As several I/O devices accept or release data at a much lower cost than the microprocessor, this technique is used to control the microprocessor to operate with an I/O device at the I/O devices data transfer rate.The drawback of the strobe approach is that the source unit that starts the transfer has no method of knowing whether the destination unit has received the data element that was located in the bus. A destination unit that initiates the transfer has no method of knowing whether the source unit ... Read More

The strobe control technique of asynchronous data transfer operates a single control line to time each transfer. The strobe can be activated by either the source or the destination unit. The diagram shows a source-initiated transfer.The data bus gives the binary data from the source unit to the destination unit. Generally, the bus has multiple lines to transfer a unified byte or word. The strobe is a single line that instructs the destination unit when an accurate data word is accessible in the bus.As displayed in the timing diagram of figure (b), the source unit first places the data on ... Read More

In this transmission, signals are sent between the computers and external systems or vice versa asynchronously. This generally defines data that is sent at infrequent intervals instead of in a steady stream, which represents that the first element of the execute file might not ever be the first to be transmitted and enter at the destination.There are different elements of the execute data that are sent in multiple intervals, frequently together, but follow several paths approaching the destination. The transfer of asynchronous data doesn’t need the coordination or timing of bits between the two endpoints.The internal operations in a digital ... Read More

Isolated I/OIn the isolated I/O configurations, the CPU has definite input and output instructions, and each of these instructions is related to the address of an interface register. When the CPU fetches and decodes the operation code of an input or output instruction, it locates the address related to the instruction into the common address lines.Simultaneously, it enables the I/O read (for input) or I/O write (for output) control line. This instructs the external elements that are connected to the common bus that the address in the address lines is for an interface register and not for a memory word.In ... Read More

There are two commonly used for organizations for multibyte data such as big-endian and little-endian. In the big-endian format, the most important byte of a value is saved in location X, the following byte in location X + 1, and so on. For example, the hexadecimal value 0102 0304H (H for hexadecimal) would be stored, starting in location 100H, as shown in table (a).Data organization in (a) big endian and (b) little endian formatsMemory AddressData (in hex)10101102021030310404(a)Memory AddressData (in hex)10104102031030210401(b)In little endian, the order is reversed. The smallest significant byte is saved in location X, the next byte in location ... Read More

There is the following technique for joining memory chips to form a memory subsystem. Two or more chips can be combined to generate a memory with more bits per location. This is done by linking the corresponding address and control signals of the chips and linking their data pins to various bits of the data bus.For example, two 8 x 2 chips can be combined to generate an 8 x 4 memory as displayed in the figure. Both chips get the equal three address inputs from the bus, and the same chip enables and output enables signals.The data chips of ... Read More

The internal organization is linear. This chip has three address inputs and two data outputs, and 16 bits of internal storage constructed as eight 2-bit locations. The three address bits are decoded to choose one of the eight locations, but only if the chip enable is active. If CE = 0, the decoder is disabled and no location is selected.The tri-state buffers for that location’s cells are enabled, authorizing data to move to the output buffers. If both CE and OE are set to 1, these buffers are enabled and the data is output from the chip, therefore, the outputs ... Read More

The instruction cycle is the process a microprocessor goes through to process an instruction. First, the microprocessor fetches or reads, the instruction from the memory. Therefore it decodes the instruction, determining which instruction it has fetched. Finally, it implements the operations required to execute the instruction. Each of these functions including fetch, decode and execute contains a sequence of one or more operations.First, the microprocessor locates the address of the instruction on the address bus. The memory subsystem inputs this address and decodes it to access the desired memory locations. After the microprocessor enables ample time for memory to decode ... Read More

A bus is a set of wires. The elements of the computer are linked to the buses. It can transfer data from one element to another, the source element outputs data onto the bus. The destination element then inputs this information from the bus. As the complexity of a computer system improves, it becomes more effective (in methods of minimizing connections) at using buses instead of a direct connection between each pair of devices.Buses use less area on a circuit board and need less power than a huge number of direct connections. It can also need fewer pins on the ... Read More

The optical disk storage system includes a rotating disk coated with a diminished layer of metal that facilitates a reflective surface and a laser beam, which is used as a read/write head for recording information onto the disk. Unlike magnetic disk, the optical layer consists of a single long track in the form of a spiral shape. The spiral shape of the track produces the optical disk applicable for reading huge blocks of sequential information onto it, including music.Types of Optical DisksThere are two types of optical disks which are as follows −Compact Disk (CD) − The terminology CD used ... Read More