Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
After going through details of device interfaces next point to be discussed is how the interface can be used to support I/O from devices. Binary information received from an external device is generally stored in memory for later processing. Information transferred from central computer in an external device initiates in memory unit. Data transfer between central computer and I/O devices can be handled in some modes. 3 techniques are possible for I/O operation. These are:
Figure below gives an general idea of these 3 techniques:
Figure: Overview of the three Input/ Output
In programmed I/O, I/O operations are fully controlled by processor. The processor executes a program which initiates, directs and terminate an I/O operation. It needs a little special I/O hardware however is quite time consuming for processor as processor has to wait for slower I/O operations to finish.
With interrupt driven I/O when interface decides that device is ready for data transfer it produces an interrupt request to the computer. Upon detecting external interrupt signal processor stops the task it was processing and branches to a service program to process I/O transfer and then returns to task it was initially performing that result in waiting time by the processor being reduced.
With both interrupt-driven and programmed I/O processor is responsible for extracting data from main memory for output and storing data in main memory during input. What about having a substitute where I/O device may directly store data or retrieve data from memory? This alternative is called direct memory access (DMA). In this mode I/O interface and main memory exchange data directly without involvement of processor.
Figure: Three techniques of I/O
How many flip-flops are required to construct mod 30 counter ? Ans. Mod - 30 counter +/- requires 5 Flip-Flop as 30 5 . Mod - N counter counts overall ' N ' number of state
Protocol used to monitor and control network devices operates at? Protocol operates at application layer to monitor and control network devices operates.
What do you understand by Hit ratio? When a processor refers a data item from a cache, if the referenced item is in the cache, then such a reference is called hit. If the refer
Linked list means node which is linked each other with a line. It means that every node is connected with another one. Every node of the list hold the reference of the next node.
nfa significance
about nano memory
In a memory hierarchy system, data and programs are first stored in secondary or auxiliary memory. Program and its related data are brought in main memory for execution. What if th
Given: • A sequence of n arrival times t0, t1, ..., tn-1, • a library of mlogically equivalent gates {(d0, c0), (d1, c1), ..., (dm-1,cm-1)} where d is delay and c is cost • a
Logic Programs: A subset of first order logic is "Logic programs". However logic program having a set of Horn clauses that are implication conjectures when there is a conjunct
What is the fundamental difference between the transactions made using Smart Card and E-cash? Smart Card and E-Cash: E-cash storable smart cards can dispense and store ca
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd