An MSP430-based system intertaces 3 external devices (ED1, ED2, ED3), each capable ot generating an interrupt request. The external devices place a request by setting the request line (a transition from a logic one to a logic zero). The request lines are connected on port1 pins as follows: P1.2 (ED3), P1.1 (ED2), and P1.0 (EDI). A request line is kept active as long as the interrupt request is pending, i.e., until the request is serviced. Answerthe following questions. A (5 points) Specifythe registers that need to be initialized at the beginning to configure the system for accepting the interrupts from the devices ED1-ED3. Fill in the table below. Note: to specify interrupts active on the falling edge the edge-selection bits should be setto 1. Register Full Name Content after initialization (binary) B. (10 points) How many ISRs are needed to process interrupts from ED1-ED3. Outline the service routine (or routines if you need multiple ones) underthe following conditions. If multiple requests occur at the same time, ED1 should have the lowest priority and ED3 the highest priority. Once in the service routine only the currently highest priority interrupt is served before exiingit. C (10 points) Assume that processing a request fromeach peripheral takes4 ms. The CPU is in a low-power mode when notexecuting the service routine(s). The following table describes a sequence of events in time. Fill in the table by answering what happens with the MSP430 on each relevant event if we know the following: ED3 and ED1 raise an interrupt request at 35 ms (assume at the same time), and ED2 raises an interrupt at 37 ms, Events are interrupt requests,entering and exiting ISRs, etc.Specify whetherthe processor is active, and if active, what portion of code is currently executing. Time 0 ms 10 ms 35 ms Event SW initialization Goto a low-powermode Requests from ED3, ED1 are received MSP430 status Active (run initialization software) An MSP430-based system intertaces 3 external devices (ED1, ED2, ED3), each capable ot generating an interrupt request. The external devices place a request by setting the request line (a transition from a logic one to a logic zero). The request lines are connected on port1 pins as follows: P1.2 (ED3), P1.1 (ED2), and P1.0 (EDI). A request line is kept active as long as the interrupt request is pending, i.e., until the request is serviced. Answerthe following questions. A (5 points) Specifythe registers that need to be initialized at the beginning to configure the system for accepting the interrupts from the devices ED1-ED3. Fill in the table below. Note: to specify interrupts active on the falling edge the edge-selection bits should be setto 1. Register Full Name Content after initialization (binary) B. (10 points) How many ISRs are needed to process interrupts from ED1-ED3. Outline the service routine (or routines if you need multiple ones) underthe following conditions. If multiple requests occur at the same time, ED1 should have the lowest priority and ED3 the highest priority. Once in the service routine only the currently highest priority interrupt is served before exiingit. C (10 points) Assume that processing a request fromeach peripheral takes4 ms. The CPU is in a low-power mode when notexecuting the service routine(s). The following table describes a sequence of events in time. Fill in the table by answering what happens with the MSP430 on each relevant event if we know the following: ED3 and ED1 raise an interrupt request at 35 ms (assume at the same time), and ED2 raises an interrupt at 37 ms, Events are interrupt requests,entering and exiting ISRs, etc.Specify whetherthe processor is active, and if active, what portion of code is currently executing. Time 0 ms 10 ms 35 ms Event SW initialization Goto a low-powermode Requests from ED3, ED1 are received MSP430 status Active (run initialization software)