Interrupt Service Routine (ISR)

Updated: April 19, 2023

In our example above, the function serint() is the ISR.

In general, an ISR is responsible for:

Depending on the complexity of the hardware device, the ISR, and the application, some of the above steps may be omitted.

Note: (QNX Neutrino 7.1 or later) The kernel saves and restores the FPU context on entering and leaving ISRs, so it's safe to use floating-point operations in them.

Let's take a look at these steps in turn.