Lpc2000

We had the same problem when we stressed the part with lots of 
interrupts: to be safe you definitely do need a default interrupt 
handler. It can be completely empty: just return. Everything works 
just fine if you do this. However, if you don't, the default value of 
zero in the default interrupt location in the VIC will cause periodic 
jumps to zero.

I can't recall the exact part we had this problem on, but my guess is 
that it's probably more than one, and the problem occurs regardess of 
the type of interrupt (we were using timer, UART0 and UART1 at the 
time the problem manifested itself).

Brendan

--- In lpc2000@yahoogroups.com, Steffen Rose <ro@p...> wrote:
> Hi,
> 
> On Wednesday 10 August 2005 20:40, you wrote:
> > I have similar problems, using vectored interrupts from UART0,
> > UART1, I2C and SPI0. It appears that you occasionally get
> > vectored to the default IRQ handler address. The default is
> > 0x00000000, (VICDefVectAddr) which equals the reset vector. I
> > will look as the CPU is resetting. If you implement a default
> > ISR and point VICDefVectAddr to the routine, you’ll find that
> > it is being called from time to time. The idea is to look at
> > VICIRQStatus to see which peripheral caused the interrupt, but
> > in my case, it is always zero. I have done some logic analyzer
> > checks, and it appears that the default ISR is called only
> > when an ISR is executing and a new IRQ is asserted. If I fond
> > out more, I’ll post it.
> 
> In our case the solution was, that a second interrupt was 
> triggered at the time we was within an interrupt routine.
> Now we added a empty default interrupt. Nothing more. The second 
> interrupt will called after returning from the first interrupt 
> routine.
> 
> 
> >> In my system are many interrupts enabled and my system resets
> >> from time to time. My idea is the occurrence of this SPURIOUS
> >> INTERRUPTS.
> 
> -- 
> Steffen Rose