TMS320F28335: There is a conflict between the shared global variables between the main loop and the interrupt service function

Hi Team,

There's an issue from the customer need your help:

How can I avoid the access conflict between the main loop and the interrupt service function to global variables?

#define OK 1 //The device status is normal#define ERROR 0 //The device status is
abnormal

#define ON 1 // Open the valve #define OFF 0 // Close the
valve

void main(void)
{
/*initialize global variable*/
volatile int status = OK; } Device status
is normal volatile int Valve = ON; Open the valve
while(1) {
if(OK == Status)
//If the
device is normal. Step.1
{
Switch = ON; Open the valve. Step.4
}
}
}

/*
* Interrupt Service Function
* Note: When an external interrupt occurs, enter the interrupt service function
*/
void ISR_Interrupt(void)
{
status = ERROR; } The device status is abnormal. Step.2
Switch = OFF; Close the valve. Step.3
}

Suppose that the CPU execution sequence is in a certain scenario: at the beginning, the value of Status is OK, and the CPU uses the if statement in the main loop to determine that the condition is true, and the "Switch = ON" statement is about to be executed. At this point, an external interrupt is triggered, and the CPU goes to the interrupt service function and executes the "Switch = OFF" statement. After all interrupted service functions are executed, the CPU returns to the place where the main loop was interrupted and continues to execute the Switch = ON statement. The final value of the switch is ON.

Best Regards,

Ben