nesting interrupts

Hi all,

I have tried to use 3 vectorized interrupts at the same time for LPC2468.

These are timer1, adc and uart1.

But after a while timer interrupt stops.

I declared all interrupt priorities as highest_priority.

IENABLE and IDISABLE macros are leaved the same as in NXP's sample code.

But timer1 interrupt gets broken.

What is the problem ?

Does not Keil manage "nesting-interrupts" ?

Thank you.

Kemal

 RE: nesting interrupts

ARM7 or more specific the ARM interrupt controller does not really support nesting interrupts, at least not more than 2 levels. There is IRQ and there is FIQ. The VIC (Vectored interrupt controller) handles priorities of interrupts that are waiting to be handled. Once one interrupt has finished, the highest priority of the waiting interrupts will be handled but it will not interrupt the previous interrupt service routine. An example how to really nest interrupts can be found on the NXP website. It requires some software overhead though and can not be part of a tool chain like the KEIL MDK but is your responsibility to implement.
http://www.standardics.nxp.com/support/documents/microcontrollers/pdf/an10381.pdf
title: AN10381 Nesting of Interrupts in the LPC2000

Hope that helps, Robert