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Methods of Data transfer are_____.
Polling
Interrupt driven
DMA
All
All
Data transfer methods define how the CPU interacts with peripheral devices to exchange information. Polling, Interrupt-driven I/O, and Direct Memory Access (DMA) represent the three primary strategies used in microprocessor systems to manage I/O operations based on system performance requirements.
Data transfer methods define how the CPU interacts with peripheral devices to exchange information. Polling, Interrupt-driven I/O, and Direct Memory Access (DMA) represent the three primary strategies used in microprocessor systems to manage I/O operations based on system performance requirements.
TtotalтАЛ=TsetupтАЛ+TtransferтАЛ тАФ General representation of total data transfer time involving CPU overhead (TsetupтАЛ) and actual data migration (TtransferтАЛ).
In Polling, the CPU continuously checks the status bit of the device. In Interrupt-driven I/O, the device signals the CPU when ready, freeing the CPU to execute other tasks. In DMA, a specialized controller manages data movement between memory and peripherals independently of the CPU, maximizing throughput.
Polling is CPU-intensive as the processor remains in a busy-wait loop.
Interrupt-driven I/O improves efficiency by eliminating unnecessary CPU checks.
DMA is the fastest method for block data transfers as it bypasses CPU cycles.
The selection of the method depends on the data rate and the latency requirements of the peripheral device.
Polling: Simple to implement, no complex hardware required.
Interrupt: High efficiency, allows CPU to perform multitasking.
DMA: Ideal for high-speed transfers like disk drives and network cards.
Polling: Wasteful of CPU time.
Interrupt: Overhead of saving and restoring context during ISR execution.
DMA: Requires complex and expensive additional hardware logic.
Keyboard monitoring in simple embedded systems (Polling).
Mouse click handling in GUI OS (Interrupt).
Audio streaming or disk I/O (DMA).
Standard I/O mapping includes memory-mapped I/O and isolated I/O.
All three listed options are valid mechanisms recognized in computer architecture curricula.
D is correct тАФ Polling, Interrupt-driven I/O, and DMA are all standard, distinct methods for handling data transfer between microprocessors and external devices.
When comparing these, remember: Polling is synchronous/blocking, Interrupts are asynchronous/reactive, and DMA is block-transfer/autonomous.