Application example: interrupt handling

AN2142

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Application example: interrupt handling

This section describes a simple ST10F27x software example making use of the interrupts. The

application uses Timers’ overflow interrupts to generate two square signals with different

frequencies on two standard port pins: P2.0 & P2.1.

The project contains 3 source files:

●

Timer.c: It contains c source code for the following project routines

–

Configure_GPT1_Timer_2(): In this routine, GPT1 Timer 2 is set up to operate in

Timer mode and is configured to generate an interrupt every 1.678 seconds.

–

Configure_GPT1_Timer_3(): In this routine, GPT1 Timer 3 is set up to operate in

Timer mode and is configured to generate an interrupt every 104.8 milliseconds.

–

Timer 2 and Timer 3 interrupts’ definitions: Timer 2 interrupt is toggling P2.0 while

Timer 3 interrupt is toggling P2.1.

●

Timer.h: It contains Timer.c routines prototypes.

●

main.c: It uses the routines described in Timer.c in order to start the two timer overflow

interrupts.

Timings suppose that the chip is operating at a frequency of 40 Mhz.

Both hardware and software environments have been setup as described in the first chapter.

The figure below shows the behaviour of the port 2 pins 0 and 1 and the GPT1 Timer 2 & Timer

3 overflow interrupts.

The example source code is located in the ’..\Example2’ directory.

For more details about the timers’ functionalities, their registers and interrupts’ handling, refer to

the ST10F27x user’s manual.