Question

Why are the read and write control lines in a DMA controller bidirectional? Under what

condition and for what purpose are they used as inputs? Under what condition and for what

purpose are they used as outputs?

Answer 1

In the CPU and DMA controllers. The DMA controller and CPU controller "share" the write and read control lines. They must all be bidirectional. As a result, we can claim that the CPU controller and the DMA controller can both regulate (activate) these lines as necessary. On the other hand, we can state that. When a DMA controller sends a Bus request input (BR) to the CPU and takes control of the Buses, these control lines go via the data buses and include control signals.