The priority encoder is a circuit that executes the priority function. The logic of the priority encoder is such that two or more inputs appear at an equal time, the input having the largest priority will take precedence. The truth table of a four-input priority encoder is given in the table. The X’s in the table designate don’t care conditions. Input I0 has the largest priority, so indifferent of the values of other inputs when this is input is 1, the output creates an output xy=00.I1 has the next priority level. The output is 01 if I1=1 supported that I0=0, ... Read More

Wormhole routing is a unique case of virtual cut-through, where the buffers at the intermediate nodes are the size of a flit. The network latency is equal to in virtual cut-through and thus autonomous of the communication distance.The advantage of wormhole routing over circuit switching and virtual cut-through appears in networks where contention is not negligible. In circuit switching, once a channel is assigned to a message, it cannot be used by other messages until the channels become free. In virtual cut-through, blocked messages should be saved in the buffer of intermediate nodes.In wormhole routing, channels can be transferred by ... Read More

There are two basic problems to be solved in any scalable computer systems such as −Tolerate and hide the latency of remote loads.Tolerate and hide idling because of synchronization between parallel processors.Remote loads are unavoidable in scalable parallel systems that use some form of distributed memory. Accessing a local memory usually requires only one clock cycle while access to a remote memory cell can take two orders of magnitude longer time. If a processor issuing a remote load operation had to wait for the operation to be completed without doing any usual work in the meantime, the remote load would ... Read More

Process scheduling is the activity of the process manager that manages the elimination of the running procedure from the CPU and the selection of another procedure based on a particular approach. The objective of the process scheduling system is to maintain the CPU busy all the time and to produce minimum response time for all programs. For reaching this, the scheduler should use specific rules for swapping processes IN and OUT of the CPU.Process scheduling involves three key concepts such as the declaration of distinct process states, the specification of the state transition diagram, and the statement of a scheduling ... Read More

USB represents Universal Serial Bus. It is an industry-standard developed in the mid-1990s that represents the cables, connectors, and communication protocols used in a bus for connection, communication, and power supply among computer and electronic devices.USB operates at 12 Mbps with particular consideration for low-cost peripherals. It provides up to 127 devices with both synchronous and asynchronous data transfers. A USB cable has a rectangular “TYPE A” plug at the computer end and a square “TYPE B” plug at the peripheral end.A Universal Serial Bus (USB) is a common interface that allows the connection between devices and host controllers including ... Read More

RS-232 is a standard communication protocol for connecting computers and their peripheral devices to enable serial data exchange. In simple terms, RS232 represents the voltage for the path used for data exchange between the devices. It determines the common voltage and signal level, common pin wire configuration and minimum, amount of control signals.RS232 represents the signals connecting between DTE and DCE. Therefore, DTE represents Data Terminal Equipment and an example for DTE is a computer. DCE represents Data Communication Equipment or Data Circuit Terminating Equipment and an example for DCE is a modem.RS232 was introduced in the 1960s and was ... Read More

UART represents Universal Asynchronous Receiver Transmitter. It is dedicated to hardware related to serial communication. UART is one of the most generally used serial communication techniques. UART is being used in several applications like GPS Receivers, Bluetooth Modules, GSM and GPRS Modems, Wireless Communication Systems, RFID-based applications, etc.Functions of the UARTThere are various functions of UART which are as follows −It can change parallel data into serial data for outbound communicationsIt can change serial data into parallel data for inbound communicationsIt can add a parity checking bit on outbound transmissions and tests the parity bit for inbound transmissionsIt can handle ... Read More

Linear Pipeline ProcessorLinear pipelining is an approach that decomposes any sequential process into limited subprocesses, which are separate from each other so that every subprocess can be implemented in a unique dedicated segment and all these segments work concurrently. Thus the whole function is divided into separate tasks and these subtasks are implemented by a segment.The concept of pipelining in computer architecture is corresponding to a technical assembly line. As in the market there multiple divisions like manufacturing, packing, and delivery division, a product is manufactured by the manufacturing division, while it is packed by the packing division a new ... Read More

Virtual memory is the partition of logical memory from physical memory. This partition supports large virtual memory for programmers when only limited physical memory is available.Virtual memory can give programmers the deception that they have a very high memory although the computer has a small main memory. It creates the function of programming easier because the programmer no longer requires to worry about the multiple physical memory available.Virtual memory works similarly, but at one level up in the memory hierarchy. A memory management unit (MMU) transfers data between physical memory and some gradual storage device, generally a disk. This storage ... Read More

DMA represents Direct Memory Access. It is a hardware-controlled data transfer method. An external device can control data transfer. The external device creates address and control signals that are needed to control data transfer. External devices also enable peripheral devices to directly access memory. The external device which controls the data transfer is known as the DMA controller.There are three different modes of DMA data transfer which are as follows −Burst Mode − In burst mode, a whole block of data is shared in one contiguous sequence. Since the DMA controller is allowed access to the system buses by the ... Read More