Consider a system with three I/O devices: a printer, a disk, and a communication line, with increasing priorities of 1, 2, and 3, respectively. A user program begins at t=0. During the execution, there are interrupts occurring in the system as follows and we assume the ISR processing time are all 10 time units for all the three devices to complete:

At t=5, a printer interrupt occurs;

At t=10, a communication interrupt occurs;

At t=15, a disk interrupt occurs

Draw the time sequence diagrams for sequential interrupt processing and nested interrupt processing