What happens when an interrupt occurs during execution interrupt routine?

[markbng]

Posted on August 31, 2005 at 14:17

What happens when an interrupt occurs during execution interrupt routine?

[markbng]

Posted on August 19, 2005 at 20:29

Hello,

At the moment I am writing a software-UART that is called upon an interrupt. The device I am using is the ST72F651. I use PA0 as interrupt input (PA0 is an input and PAOR0 is set).

What happens if the interrupt routine is handling a PA0 interrupt and another PA0 interrupt event happens while this routine is being executed? Will the controller ignore this interrupt on the PA0 input or will the interrupt call be pended? If these interrupts are pended, should I first disable the interrupt in the interrupt routine by clearing the PAOR0 bit?

Thanks for your help.

Kind regards,

Mark

[sjo]

Posted on August 22, 2005 at 14:24

The interrupts on the st7 are anded and as such the other interrupt will be missed. To make the other interrupt pending clear the OR register bit for the active interrupt.

Have a look at the following doc

http://www.st.com/stonline/books/pdf/docs/6055.pdf

Regards

sjo

[franco]

Posted on August 31, 2005 at 14:17

Thanks for the link Sjo..