Lpc2000

Hi all,

I have an IRQ problem. My program did not jump after interrupt 
occured. Now I'm using 2 IRQs (I don't want to use FIQ) and I assign 
IRQ 0 for Timer1 and IRQ 1 for Timer0.

VICIntSelect = 0

For Timer1:

VICIntEnable |= 0x00000020;
VICVectAddr = (unsigned long)Func_A;
VICVectCntl0 = 0x25;

For Timer0:

VICVectAddr = (unsigned long)Func_B;
VICVectCntl0 = 0x24;
VICIntEnable |= 0x00000010; 

In simulator, the addresses of Func_A and Func_B were loaded in 
vector table properly. But when interrupt occured (RawInt = 1), the 
program didn't jump to those function. I think my Startup.s is not 
correct. I don't know how to define addresses of 2 function for IRQs.

-------------------------------------------
Vectors:        LDR     PC, Reset_Addr         
                LDR     PC, Undef_Addr
                LDR     PC, SWI_Addr
                LDR     PC, PAbt_Addr
                LDR     PC, DAbt_Addr
                NOP                            /* Reserved Vector */
                LDR     PC, IRQ_Addr
                LDR     PC, FIQ_Addr

Reset_Addr:     .word   Reset_Handler
Undef_Addr:     .word   Undef_Handler
SWI_Addr:       .word   SWI_Handler
PAbt_Addr:      .word   PAbt_Handler
DAbt_Addr:      .word   DAbt_Handler
                .word   0                      /* Reserved Address */
IRQ_Addr:       .word   IRQ_Handler
FIQ_Addr:       .word   FIQ_Handler

Undef_Handler:  B       Undef_Handler
SWI_Handler:    B       SWI_Handler
PAbt_Handler:   B       PAbt_Handler
DAbt_Handler:   B       DAbt_Handler
IRQ_Handler:    B       IRQ_Handler  /* ?????????? */
FIQ_Handler:    B       FIQ_Handler

------------------------------------------------

It seems program always jump to IRQ_Handler address. If I assign 
Func_A to IRQ_Handler

IRQ_Handler:    B       Func_B

Program will jump to Func_B when interrupt occurs. I used to hook 
these 2 function with FIQ and IRQ Handler. It worked well. But for 2 
IRQs, I don't know how to define them.


Does anyone know can help me?

Thanks,

Teera.

At 07:03 PM 3/17/05 +0000, tphatrapornnant wrote:
>I have an IRQ problem. My program did not jump after interrupt
>occured. Now I'm using 2 IRQs (I don't want to use FIQ) and I assign
>IRQ 0 for Timer1 and IRQ 1 for Timer0.

<snip>

>In simulator, the addresses of Func_A and Func_B were loaded in
>vector table properly. But when interrupt occured (RawInt = 1), the
>program didn't jump to those function. I think my Startup.s is not
>correct. I don't know how to define addresses of 2 function for IRQs.

<snip>
>It seems program always jump to IRQ_Handler address. If I assign
>Func_A to IRQ_Handler
>
>IRQ_Handler:    B       Func_B
>
>Program will jump to Func_B when interrupt occurs. I used to hook
>these 2 function with FIQ and IRQ Handler. It worked well. But for 2
>IRQs, I don't know how to define them.
<snip>

 From a quick look, I think you are correct.  The IRQ in startup.s needs to 
read the vector from the VIC and jump to it.  I think there are examples in 
the files section.  I know that the newlib-lpc  at 
http://www.aeolusdevelopment.com has a GNU startup that has this routine in 
it (it's really just a different type of jump instruction in the table).

The interrupt routines for each of your Func_A and Func_B above need to be 
defined with your compilers equivalent of an interrupt keyword (if you 
trust it) or have a small assembly shell to take care of the necessary details.

BTW if you don't read and write to the VIC address register the 
corresponding interrupt won't be dismissed.

Robert

" 'Freedom' has no meaning of itself.  There are always restrictions,   be 
they legal, genetic, or physical.  If you don't believe me, try to chew a 
radio signal. "  -- Kelvin Throop, III
http://www.aeolusdevelopment.com/