In a dma employed system, an i/o device has a data transfer rate of 100kbps and wants to transfer a block of 256 bytes where the data are transferred two bytes at a time. in the same system, bus control transfer takes 100 ns each way, i. e., from i/o device to processor or vice versa. the bus cycles takes 200 ns.

a. how long would the device tie up the bus when transferring the block in a burst mode, i. e., the dma interface gains bus mastership prior to the start of a block transfer and maintains control of the bus until the whole block is transferred?

b. repeat the calculation for cycle-stealing mode.