Arrange the following in the increasing order of complexity. (a) I/O Module…

Answer (in increasing order of complexity): I/O Module < DMA < I/O Channel < I/O Processor.

• I/O Module: A simple device interface providing control and status registers. It relies on the CPU to manage data transfers (via polling or interrupts), so it is the least complex.

• Direct Memory Access (DMA): A dedicated controller that moves blocks of data directly between devices and main memory without continuous CPU intervention. It requires address, count and control logic, so it is more complex than a basic I/O module.

• I/O Channel: Specialized hardware that can execute sequences of I/O commands (often using microcode) and manage multiple devices and higher-level I/O operations, offloading more work from the CPU than DMA.

• I/O Processor: A full, independent processor dedicated to I/O tasks with its own instruction set and ability to run control programs/drivers. It provides the highest autonomy and is the most complex.

Therefore, the correct increasing order by complexity is: I/O Module < DMA < I/O Channel < I/O Processor.