Notes about interrupt and exceptions

Interrupts occur at random times during the execution of a program, in response to signals from hardware. System hardware uses interrupts to handle events external to the processor, such as requests to service peripheral devices. Software can also generate interrupts by executing the INT n instruction.

Source of interrupts:

• External (hardware)

• Internal (software, int)

  Maskable:

Any external (hardware) interrupt that is delivered to the processor by means of the INTR pin or through the local APIC is called a maskable hardware interrupt.

¿ Mask: disable | Unmask: enable ? (Has to be 100% checked)

Exceptions occur when the processor detects an error condition while executing an instruction, such as division by zero. The processor detects a variety of error conditions including protection violations, page faults, and internal machine faults.

Source of exceptions:

• Processor-detected program-error exceptions.
• Software-generated exceptions.
• Machione-check exceptions

Exceptions are classified as:

• Faults (can be restored)
• Traps (can be continued, just stopped)
• Aborts (severe errors)