Table of Contents
- 1 What is interrupt driven IO?
- 2 What is the difference between interrupt driven I O and DMA?
- 3 What are the advantages of using interrupt driven IO over programmed IO?
- 4 What is programmed I O and memory mapped I O?
- 5 How is DMA better than programmed data transfer?
- 6 What is the advantage of programmed IO over memory mapped IO?
- 7 What are the differences between memories mapped I O and I O mapped I O?
- 8 What is the difference between processor and DMA controller?
- 9 What is the difference between interrupt-driven I/O and processor-driven I/O?
- 10 What is interrupt initiated I/O mode?
What is interrupt driven IO?
Interrupt driven I/O is an alternative scheme dealing with I/O. Interrupt I/O is a way of controlling input/output activity whereby a peripheral or terminal that needs to make or receive a data transfer sends a signal. This will cause a program interrupt to be set.
What is the difference between interrupt driven I O and DMA?
The DMA module transfers the entire block of data, one word at time, directly to or from memory, without going through the processor. Whereas in Interrupt-driven I/O, device itself inform the CPU by generating an interrupt signal. If the data rate of the I/O is too fast. Data may be lost.
What are the advantages of using interrupt driven IO over programmed IO?
The main advantage is reduced latency. The processor has to temporarily halt it’s work in programmed I/O, whereas in interrupt I/O, the processor continues to perform and only halts when interrupt is received.
What is program io?
Programmed I/O is implicated to data transfers that are initiated by a CPU, under driver software control to access Registers or Memory on a device. With programmed I/O, data are exchanged between the processor and the I/O module. If the processor is faster than the I/O module, this is wasteful of processor time.
What is the primary advantage of interrupt driven I O over programmed or polling I O?
In interrupt driven data transfer, whenever I/O device is ready for the data transfer, it will interrupt the CPU. In the ISR, the CPU will perform the data transfer. This method is better than polling because here the CPU does not have to waste time in checking the status of the I/O device.
What is programmed I O and memory mapped I O?
The term Programmed I/O can refer to either Memory-mapped I/O (MMIO) or Port-mapped I/O (PMIO). PMIO refers to transfers using a special address space outside of normal memory, usually accessed with dedicated instructions, such as IN and OUT in x86 architectures.
How is DMA better than programmed data transfer?
PIO stands for Programmed Input/Output, which is a protocol for data transfer. Since it involves the CPU, the use of PIO mode for data transfer can slow a computer down considerably. On the contrary, DMA (Direct Memory Access) does not involve the CPU. Therefore, DMA has better performance in data transfer than PIO.
What is the advantage of programmed IO over memory mapped IO?
Thus, an advantage of memory-mapped I/O is that this large repertoire of instructions can be used, allowing more efficient programming. A disadvantage is that valuable memory address space is used up….Programmed I/O.
| Advantages | – simple to implement |
|---|---|
| Disadvantages | – ties up CPU for long period with no useful work |
Why do most programs use interrupt driven I O over busy wait?
Busy-wait I/O may be the cheapest implementation for systems that need to do only one thing at a time. Interrupt driven I/O is preferable when the I/O is time critical as well as in a multi-threaded process/system.
Where is programmed IO used?
The best known example of a PC device that uses programmed I/O is the AT Attachment (ATA) interface and Serial ATA interface; however, the AT Attachment interface can also be operated in any of several DMA modes.
What are the differences between memories mapped I O and I O mapped I O?
Solution
| Memory mapped I/O | |
|---|---|
| 1 | I/O is assigned to the separate address space of memory. |
| 2 | Separate control signal is not required. |
| 3 | Memory space is reduced due to insertion of I/O address. |
| 4 | It requires 16-bit address bus |
What is the difference between processor and DMA controller?
CPU initiates the the transfer by providing appropriate grant signals to the data bus. And passes the control to the DMA controller which controls the rest of the data transfer and transfers the data directly to I/O device. During this time, CPU continues with other instructions.
What is the difference between interrupt-driven I/O and processor-driven I/O?
The important thing to consider here is that processor is way more faster than the I/O module and thus have to wait for a long time to respond. In case of interrupt-driven I/O, processor after requesting the I/O module proceeds with its normal work. After I/O device has completed the request, it notifies the processor using an interrupt.
What is the meaning of programmed I/O?
Programmed I/O. Programmed I/O is the simplest I/O technique for exchanging data between processor and other external device. In Programmed I/O processor executes a program that gives the direct control of I/O operation. Processor issue a command to the I/O module and wait until the operation is complete.
What is interinterrupt I/O?
Interrupt I/O is something similar to Programmed I/O technique. At this technique the processor do not wait for until the I/O operation is complete. Rather processor normally do the other task. When I/O is complete the I/O module interrupt into processor .
What is interrupt initiated I/O mode?
2. Interrupt Initiated I/O : This mode uses an interrupt facility and special commands to inform the interface to issue the interrupt command when data becomes available and interface is ready for the data transfer. In the meantime CPU keeps on executing other tasks and need not check for the flag.