31 Lecture
CS501
Midterm & Final Term Short Notes
Direct Memory Access (DMA)
Direct Memory Access (DMA) is a technique that allows data to be transferred between peripheral devices and memory without the intervention of the processor. DMA controllers are used to manage the transfer of data, freeing up the processor to pe
Important Mcq's
Midterm & Finalterm Prepration
Past papers included
Download PDF
- What is DMA?
a) A technique that allows data to be transferred between peripheral devices and memory without the intervention of the processor.
b) A method to transfer data using the processor as an intermediary.
c) A technique to improve the processing speed of the processor.
d) None of the above.
Answer: a
What is the primary function of DMA?
a) To reduce the load on the processor by allowing data transfers without its intervention.
b) To increase the processing speed of the processor.
c) To control the flow of data between the processor and peripherals.
d) None of the above.
Answer: a
Which of the following devices can benefit from DMA?
a) Keyboard
b) Mouse
c) Hard disk
d) All of the above
Answer: d
Which of the following is not a benefit of using DMA?
a) Reducing the load on the processor
b) Faster data transfer rates
c) Better control of data flow between peripherals and the processor
d) None of the above
Answer: c
Which component is used to manage the transfer of data using DMA?
a) Peripheral devices
b) Memory
c) DMA controller
d) Processor
Answer: c
Which of the following is a disadvantage of using DMA?
a) It can result in memory fragmentation.
b) It can result in data corruption.
c) It can result in slower data transfer rates.
d) None of the above.
Answer: b
Which of the following is not a type of DMA transfer?
a) Single
b) Burst
c) Cycle-stealing
d) Multitasking
Answer: d
Which of the following is an example of a peripheral device that can initiate DMA transfers?
a) Hard disk
b) Graphics card
c) Sound card
d) All of the above
Answer: d
Which of the following is a limitation of DMA?
a) It can only transfer data in one direction.
b) It can only transfer small amounts of data.
c) It requires a lot of processor resources to function.
d) None of the above.
Answer: a
Which of the following is an advantage of DMA over programmed I/O?
a) It reduces the load on the processor.
b) It allows for faster data transfer rates.
c) It improves the control of data flow between peripherals and the processor.
d) All of the above.
Answer: d
Subjective Short Notes
Midterm & Finalterm Prepration
Past papers included
Download PDF
- What is Direct Memory Access (DMA)?
Answer: DMA is a technique that allows data to be transferred between peripheral devices and memory without the intervention of the processor.
What is the primary function of DMA?
Answer: The primary function of DMA is to reduce the load on the processor by allowing data transfers without its intervention.
How does DMA improve system performance?
Answer: DMA improves system performance by reducing the load on the processor and allowing for faster data transfer rates.
What is a DMA controller?
Answer: A DMA controller is a component that is used to manage the transfer of data using DMA.
What are the types of DMA transfers?
Answer: The types of DMA transfers include single, burst, and cycle-stealing transfers.
Can DMA be used with all types of peripheral devices?
Answer: Yes, DMA can be used with all types of peripheral devices.
What is the disadvantage of using DMA?
Answer: One disadvantage of using DMA is that it can result in data corruption.
How is DMA different from programmed I/O?
Answer: DMA allows for faster data transfer rates and reduces the load on the processor, while programmed I/O requires the processor to transfer data between peripheral devices and memory.
Can DMA transfer data in both directions?
Answer: No, DMA can only transfer data in one direction.
Is DMA widely used in modern computer systems?
Answer: Yes, DMA is widely used in modern computer systems to improve system performance.
Direct Memory Access (DMA) is a technique that allows data to be transferred between peripheral devices and memory without the intervention of the processor. This technique frees up the processor to perform other tasks, improving system performance by reducing the load on the processor and allowing for faster data transfer rates.
DMA controllers are used to manage the transfer of data. The controller takes control of the bus from the processor and performs the data transfer between the peripheral device and memory. This frees up the processor to perform other tasks, reducing the overall processing time and increasing system efficiency.
There are several types of DMA transfers, including single, burst, and cycle-stealing transfers. Single transfers involve transferring a single unit of data, burst transfers involve transferring a block of data, and cycle-stealing transfers involve the DMA controller stealing a cycle from the processor to perform the transfer.
DMA can be used with all types of peripheral devices, including keyboards, mice, hard disks, and graphics cards. It can be initiated by either the processor or the peripheral device. DMA is widely used in modern computer systems to improve system performance.
One disadvantage of using DMA is that it can result in data corruption. This can occur if the DMA controller accesses a portion of memory that is currently being used by the processor or another device. However, this can be prevented by proper programming and management of the DMA controller.
Overall, DMA is a powerful technique that can significantly improve system performance by reducing the load on the processor and allowing for faster data transfer rates. It is a widely used technique in modern computer systems, and its proper use can lead to increased system efficiency and overall performance.