Detecting how much time for external interrupts in MPC5746C from NXP

[ahmedsaber]

Hello All,

I'm trying to measure the time of an external event staying outside this controller MPC5746C.

This controller supports only the detection of the external interrupt on either the rising or the falling edge.

Assume that I configured a pin to be used within the SUIL2 module to detect an external event"SUIL2 module is the responsible for the external interrupts handling"

I configured this pin to be by default at low level, once the external event is present it will pull up the pin level to be at high level



I configured an ISR to be fired on the rising edge of this pin level, so once the external event is present I got the ISR, which I will serve till it ends.

may be the external event lasts for one seconds or two or whatever, may be it will lasts even after the ISR is served.

And I will not get the ISR again because there is no additional edges as the pin level kept at high level



So how can I detect the end of the external event ?

" knowing that I can't also read the pin level within the software because it must be configured as GPIO to be able to read it's value while it is configured to be an external events detector pin"

Thanks a lot

 

[FvM]

knowing that I can't also read the pin level within the software because it must be configured as GPIO to be able to read it's value while it is configured to be an external events detector pin

Is it so? Sounds strange for a modern microcontroller. You may consider to change the pin configuration on the fly.

 

[ahmedsaber]

You may consider to change the pin configuration on the fly.

I configured the ISR to be triggered with the rising edge and within the ISR changed the configuration to be triggered on the falling edge hoping to catch the second edge of the same pulse, but I didn't get the ISR again , I'm not sure why