Question

Which of the following must be true for the RFE (Returns from Exception) instruction on a general purpose processor.

1. It must be a trap instruction

2. It must be a privileged instruction

3. An exception can not be allowed to occur during execution of an RFE instruction.

• A. 1, 2 and 3 only
• B. 1 only
• C. 2 only
• D. 1 and 2 only

Answer 1

The correct option is A 1, 2 and 3 only

A RFE (Return From Exception) instruction contains a trap instruction, privileged instruction and an exception can't be allowed to occur during the execution of an REF instruction.