DPSD Quiz 1

Mark whichever is correct for Memory mapped I/O scheme.

• The I/O device and the memory have separate address space.

• The I/O device and the memory shares same address space.

• No special command for I/O is needed

• Needs I/O or memory select line

In ____________ mode, the I/O module and main memory exchange data directly, without processor involvement.

• Programmed I/O

• DMA

• Interrupt-driven I/O

• All the above

A CPU generally handles an interrupt by executing an interrupt service routine

• As soon as an interrupt is raised

• By checking the interrupt register at the end of fetch cycle

• By checking the interrupt register after finishing the execution of the current instruction

• By checking the interrupt register at fixed intervals.

A DMA module is transferring characters (8-bit) to memory using cycle stealing from a device transmitting at 9600 bps. The processor is fetching instructions at the rate of 1 million instructions per second (1 MIPS). By how much will the processor be slowed down due to the DMA activity?

• 0.10%

• 0.12%

• 0.24%

• 0.5%

What is the purpose of an interrupt service routine in a CPU?

• To handle interrupts at fixed intervals

• To check the interrupt register at the end of the fetch cycle

• To execute instructions in the absence of interrupts

• To handle interrupts by checking the interrupt register after finishing the execution of the current instruction

What is a characteristic of the memory mapped I/O scheme?

• The I/O device and the memory have separate address space

• No special command for I/O is needed

• Requires I/O or memory select line

• The I/O device and the memory share the same address space

What is the role of a DMA controller in a computer system?

• To handle interrupts at fixed intervals

• To transfer data between I/O devices and main memory

• To execute instructions in the absence of interrupts

• To handle interrupts by checking the interrupt register after finishing the execution of the current instruction

What is the significance of cycle stealing in DMA operations?

• It allows the DMA controller to steal cycles from the CPU to transfer data

• It allows the CPU to steal cycles from the DMA controller for processing instructions

• It prevents the DMA controller from interfering with the CPU's operation

• It ensures that the DMA controller operates at the same speed as the CPU

In ____________ mode, the I/O module and main memory exchange data directly, without processor involvement.

• Programmed I/O

• DMA

• Interrupt-driven I/O

• All the above

What is the function of an input/output controller in a computer system?

• To handle interrupts at fixed intervals

• To transfer data between I/O devices and main memory

• To execute instructions in the absence of interrupts

• To handle interrupts by checking the interrupt register after finishing the execution of the current instruction