Lpc2000

--- In lpc2000@yahoogroups.com, "sig5534" <sig5534@h...> wrote:
> 
> This is my first ARM7 project, so I am sure I must be missing 
> something really simple, but I sure can't find what it is.
> 
> I'm using JetJTAG debugger and the IAR compiler, and a bit of 
MakeApp 
> stuff.  I didn't trust what MakeApp was doing so I put my own 
manual 
> VIC init calls in after their init.  But same problem persists.
> 
> I'm trying to get the TIMER-0 INT to fire.  The counter is setup 
and 
> running, and it looks like all of the INT flags go off in the T0 
and 
> VIC as they should, but yet it never jumps into the ISR routine.
> 
> I have TIMER0(VIC-CH4) set to go to IRQ slot-0.
> 
> Here's what the T0 and VIC registers look like after it runs:
> 
> T0IR	0x0001  (Int Flag Tripped, yes?)
> T0TCR	0x0001  (Counter enabled)
> 
> VICFIQStatus	0x0000
> VICIRQStatus	0x0010 (Int flag tripped for T0, yes?)
> VICRawIntr	0x2018
> VICIntSelect	0x0020  (I have T1 set to go to FIQ later)
> VICIntEnable	0x0070
> VICSoftInt	0x0000
> VICProtection	0x0000
> VICDefVectAddr	0x0948
> VICVectAddr	0x095C 
> VICVectAddr0	0x095C ( correct ISR adr)
> VICVectCntl0	0x0024 (T0 is VIC-CH4, and Enabled)
> 
> If I understand this, the INT flag in VICIRQStatus is tripped 
> correctly.  So why is it not taking the jump to the ISR adr?


Do you have the "LDR PC, [PC, #-0x0FF0]" at address 0x18 in the 
exception vectors?

Have you reserved a suitable IRQ stack and initialized its stack 
pointer in the startup code?

Have you enabled IRQ in the CPU (like "msr cpsr_c, #0x1F") in the
startup code?


Karl Olsen