# Software simulator for MCS51

This screenshot demonstrates window which displays interrupt system of the microcontroller. Interrupt enable register and priority register as well as interrupt request bits are displayed in this window. Note that if you set some request bit during simulation and interrupt is enabled, the CPU will accept the interrupt and responding to it by starting the service routine.

The `Interrupt/program rate' pane shows ratio of execution time of main program and interrupt service routines. Content of this pane is not saved if you close tha window which means that measure of the ratio is restarted every time you reopen the window.