Question

QUESTION 11

1. Which instruction is used to return from a user function to its caller?

   		return
   		eret
   		jal
   		jr

1 points   

QUESTION 12

1. Which of the following is the best description of memory mapped input/output (MMIO)?

   		the ability to use a common address space to access memory as well as input/output devices.
   		the ability to read characters from the keyboard
   		the ability to interrupt the CPU when the result of an operation involving an IO device is complete.
   		the ability to store the output from an IO device in memory.

1 points   

QUESTION 13

1. Which of the following is a requirement for making a function re-entrant?

   		The program counter must be saved prior to the invocation of another function or interrupt handler.
   		The function should have an appropriate return statement at the end of its body.
   		All temporary register values must be saved on the stack prior to the invocation of another function or interrupt handler.
   		The function should use the stack for all input parameters and return values.

Answer 1

Question 11

Answer is return

Whenever we encounter a return statement, we will go back to the calling function.

Question 12

Memory-mapped input/output (MMIO) is the ability to use a common address space to access memory as well as input/output devices

Question 13

The correct answer is "The program counter must be saved prior to the invocation of another function or interrupt handler"

Whenever we have an interrupt, we will save the address in the program counter. We will first solve the interrupt and then resume execution from the same address where we left through the program counter.