It is necessary to transfer 2048 words from a hard drive to a section of memory starting from address 4096. The transfer is by means of DMA, as shown in Figure 11-20.

Figure 11-20

(a) Give the initial values that the CPU must transfer to the DMA controller.

(b) Give the step-by-step account of the actions taken during the input of the first two words.

Transcribed Image Text:

Address decoder Interrupt BG BR RD BG CPU WR Address Data RD WR Address Data DS RS BR Interrupt DMA controller Read control RD WR Address Data Write control Address bus Memory Data bus DMA request DMA acknowledge I/O peripheral device