[amp_mcq option1=”Interrupt and NMI” option2=”NMI and PSW” option3=”Interrupt vector and memory refresh” option4=”NMI and memory refresh” correct=”option2″]
The correct answer is: B. NMI and PSW
The NMI (Non-Maskable Interrupt) is a special type of interrupt that can’t be ignored by the CPU. It’s used for events that need to be handled immediately, such as a power failure or a hardware error. The PSW (Program Status Word) is a register that stores the current state of the CPU, including the instruction that was being executed when the interrupt occurred.
The other options are incorrect because:
- Option A: Interrupt and NMI are both registers, but they are not additional registers. They are part of the standard Z80 register set.
- Option C: Interrupt vector is a memory location that stores the address of the interrupt service routine. It is not a register.
- Option D: Memory refresh is a process that is used to keep the contents of dynamic RAM (DRAM) from decaying. It is not a register.