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External Interrupt

Trigger downstream function-call subsystem from interrupt service routine

Since R2021a

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Add-On Required: This feature requires the Simulink Support Package for Raspberry Pi Hardware add-on.

  • Raspberry Pi External Interrupt block icon

Libraries:
Simulink Support Package for Raspberry Pi Hardware / Basic

Description

The External Interrupt block triggers a downstream Function-Call Subsystem from an interrupt service routine (ISR). The Function-Call Subsystem should be connected to the output port of the External Interrupt block. An ISR is a section of code triggered by the Raspberry Pi® kernel when the interrupt occurs at the hardware pin you specify.

During simulation, you can provide an input to the External Interrupt block by connecting a source block from the Simulink® library to the input port of the External Interrupt block. The External Interrupt block receives an input value of 0 or 1 at each time step. When the input at the block port is 1, the block triggers the downstream function-call subsystem. When the input at the block port is 0 or when no source of input is connected to the input port of the block, the block does not trigger the downstream function-call subsystem. During code generation, any Simulink block connected to the input port of the External Interrupt block is ignored and has no effect on the generated code.

Note

We recommend that you use the External Interrupt block only in the parent model in a model hierarchy. For more information, refer to Model References.

Ports

Input

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During simulation, you can simulate an input to the External Interrupt block by connecting a source block from the Simulink library to the SimIRQ port. If the input provided to the block is boolean true, the block triggers the downstream function-call subsystem. The External Interrupt block receives an input value of 0 or 1 at each time step. When the input at the block port is 1, the block executes the Function-Call Subsystem. If you do not provide an input, the block triggers the downstream function-call subsystem until the simulation continues to run. During code generation, any Simulink block connected to the input port of the External Interrupt block is ignored and has no effect on the generated code.

Dependencies

To enable this port, select the Add simulation input port parameter.

Data Types: Boolean

Output

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Sends function-call events to the function-call input port of a function-call subsystem or model.

Parameters

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Select the Raspberry Pi hardware board.

Click View pin map to view the pin mapping diagram associated with the Raspberry Pi hardware board that you select.

Select the digital input pin on the Raspberry Pi hardware to generate external interrupts. When using multiple Raspberry Pi boards, you can select different pins for each of the boards.

Select one of these modes.

  • Pull-up: When you select this mode, the pin you set in the Pin parameter is pulled up to logic high when no input is connected to the pin.

  • Pull-down: When you select this mode, the pin you set in the Pin parameter is pulled down to logic low when no input is connected to the pin.

Select the edge selection mode to specify which signal transitions on the selected Raspberry Pi hardware pin trigger the downstream function call.

  • Rising: When the digital pin value goes from low to high

  • Falling: When the digital pin value goes from high to low

  • Either: When the digital pin value goes from either low to high or high to low

This figure shows how the block executes the downstream function call as the hardware pin value changes in different interrupt modes.ISR triggered in different interrupt modes.

Note

For any Edge selection mode that you select, you can expect a delay in the downstream function call that is close to the base rate of the Simulink model.

This parameter enables the SimIRQ input port. To provide an input to the block during simulation, connect a source block to the SimIRQ input port. During code generation, any block connected to the port is ignored and has no effect on the generated code.

Version History

Introduced in R2021a

See Also

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