The Or1ksim ISS library is extended to provide API calls to generate an interrupt. The Or1ksim includes a programmable interrupt controller (PIC), which is enabled. The new API call, or1ksim_interrupt, provides an edge-triggered interrupt, and takes as parameter the interrupt number to be triggered. The new API calls, or1ksim_interrupt_set and or1ksim_interrupt_set, provide for setting and clearing level sensitive interrupts. The choice of interrupt type to use is made in the Or1ksim configuration file.

The Or1ksim wrapper, Or1ksimDecoupSC is further extended by a new derived class, Or1ksimIntrSC, which provides an array of signal ports to connect to external devices which wish to generate interrupts.