GATE | GATE-CS-2016 (Set 1) | Question 41

The size of the data count register of a DMA controller is 16 bits. The processor needs to transfer a file of 29,154 kilobytes from disk to main memory. The memory is byte addressable. The minimum number of times the DMA controller needs to get the control of the system bus from the processor to transfer the file from the disk to main memory is _________

Note : This question was asked as Numerical Answer Type.
(A) 3644
(B) 3645
(C) 456
(D) 1823


Answer: (C)

Explanation: Size of data count register of the DMA controller = 16 bits
Data that can be transferred in one go = 2¹⁶ bytes = 64 kilobytes
File size to be transferred = 29154 kilobytes
So, number of times the DMA controller needs to get the control of the system bus from the processor to transfer the file from the disk to main memory = ceil(29154/64) = 456

Thus, C is the correct answer.

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