External Interrupt Workflow for Texas Instruments C2000 Processors
This topic helps you with the workflow for external interrupts in a Simulink® model. To get started, perform these steps.
- Create or open a Simulink model. 
- Add an C28x Hardware Interrupt block to the Simulink model.  
- The hardware pin on which the interrupt is connected is specified in the Configuration Parameters dialog box. In the Simulink model, navigate to Modeling > Model Settings to open the Configuration Parameters dialog box. In the Configuration Parameters dialog box, navigate to Hardware Implementation > Target hardware resources > Input X-BAR. - For example, consider pin - 60of F28379D Launch pad is used for external interrupt. Set INPUT4 pin assignment parameter value to- 60. 
- The interrupt pin is configured to detect rising, falling or both rising and falling edge. To configure, navigate to Configuration Parameters > Hardware Implementation > Target hardware resources > External interrupt. - The input pin 60 you selected earlier is reflected in XINT1 GPIO parameter. Select the required XINT1 Polarity. - Rising edge:This interrupt triggers when the pin voltage transitions from low to high voltage (0V to a positive voltage).
- Falling edge:This interrupt triggers when the pin voltage transitions from high to low voltage (positive voltage to 0V).
- Falling and rising edge:This interrupt triggers when the pin voltage transitions from low to high voltage (0V to a positive voltage) and high to low voltage (positive voltage to 0V).
  
- Double-click the C28x Hardware Interrupt block to open the block parameters dialog. - Specify the values for CPU interrupt numbers and PIE interrupt numbers parameters. For information on PIE and CPU interrupt numbers, see C28x Hardware Interrupt. - For the considered pin 60 example, PIE value is - 4and CPU value is- 1as shown below. - Specify the Simulink task priorities and Preemption flags as required.  
- Add a Function-Call Subsystem block in the Simulink model. - The logic to be executed on the interrupt trigger is placed inside the function call subsystem.  
- Connect the output of External Interrupt block to the Function Call input of Function-Call Subsystem block. 
- In the Simulink model, navigate to Modeling > Model Settings to open the Configuration Parameters dialog box. 
- In the Configuration Parameters dialog box, navigate to Solver > Tasking and sample time options and then select Automatically handle rate transition for data transfer option. Click Apply and OK. - Note - If block with latched interrupts are placed inside the Function-Call Subsystem block, then follow the steps mentioned in Workaround to Reset Interrupt Pin of Sensors Supporting Latched Interrupts.