Lpc2000

David Hawkins wrote:
>>YES, something like that! ;-) But without nesting and change of cpu-mode.
> 
> 
> Then perhaps this :)
> 
> irq_isr:
>      sub   lr, lr, #4
>      stmfd sp!, {r0-r3, ip, lr}
>      bl irq_handler
>      ldmfd sp!, {r0-r3, ip, pc}^
> 
> 
> /* VICVectAddr dispatch loop */
> void irq_handler(void)
> {
> 	/* Process IRQ interrupts */
> 	irq_handler_t handler;
> 	while (VICIRQStatus) {
> 		/* Get the address of the highest priority handler */
> 		handler = (irq_handler_t)VICVectAddr;
> 
> 		/* Execute the handler */
> 		(*handler)();
> 
> 		/* Acknowledge the VIC */
> 		VICVectAddr = 0;
> 	}
> }
> 

Wonderful! ;-)
But why to save r0..r3 and ip in your irq_isr?!? Only lr will be changed by bl and registers used by
irq_handler() should be saved in its function prologue by irq_handler() itself!

Sten
-- 
/************************************************
 Do you need a tiny and efficient real time
 operating system (RTOS) with a preemtive
 multitasking for LPC2000 or AT91SAM7?

   http://nanortos.net-attack.de/

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   http://www.net-attack.de/

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