Interrupt handling using grab() and ungrab() sequencer in UVM !!!

One of the basic functionality on the processor interface of a verification environment is to service interrupts along with register read / write operations. Servicing the interrupt requires  stoping the ongoing register access sequence and executing the ISR sequence . This can be achieved  using grab()  method on the sequencer on an interrupt to stop the register read/write sequence and execute the interrupt sequence. ungrab() method should be used to return the sequencer control back to the register read/write sequence.