Difference between Maskable and Non Maskable Interrupt
An interrupt is an event caused by a component other than the CPU. It indicates the CPU of an external event that requires immediate attention. Interrupts occur asynchronously. Maskable and non-maskable interrupts are two types of interrupts. 1. Maskable Interrupt : An Interrupt that can be disabled or ignored by the instructions of CPU are called as Maskable Interrupt.The interrupts are either edge-triggered or level-triggered .
Eg: RST6.5,RST7.5,RST5.5 of 8085
2. Non-Maskable Interrupt : An interrupt that cannot be disabled or ignored by the instructions of CPU are called as Non-Maskable Interrupt.A Non-maskable interrupt is often used when response time is critical or when an interrupt should never be disable during normal system operation. Such uses include reporting non-recoverable hardware errors, system debugging and profiling and handling of species cases like system resets.
Eg: Trap of 8085
Difference between maskable and nonmaskable interrupt :
SR.NO. | Maskable Interrupt | Non Maskable Interrupt |
---|---|---|
1 | Maskable interrupt is a hardware Interrupt that can be disabled or ignored by the instructions of CPU. | A non-maskable interrupt is a hardware interrupt that cannot be disabled or ignored by the instructions of CPU. |
2 | When maskable interrupt occur, it can be handled after executing the current instruction. | When non-maskable interrupts occur, the current instructions and status are stored in stack for the CPU to handle the interrupt. |
3 | Maskable interrupts help to handle lower priority tasks. | Non-maskable interrupt help to handle higher priority tasks such as watchdog timer. |
4 | Maskable interrupts used to interface with peripheral device. | Non maskable interrupt used for emergency purpose e.g power failure, smoke detector etc . |
5 | In maskable interrupts, response time is high. | In non maskable interrupts, response time is low. |
6 | It may be vectored or non-vectored. | All are vectored interrupts. |
7 | Operation can be masked or made pending. | Operation Cannot be masked or made pending. |
8 | RST6.5, RST7.5, and RST5.5 of 8085 are some common examples of maskable Interrupts. | Trap of 8085 microprocessor is an example for non-maskable interrupt. |
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