Re: How to handle very fast repeating interrupts?

["Martin Laabs" <martin.laabs@mailbox.tu-dresden.de>]

Hello,

On Sun, 15 Feb 2009 23:33:55 +0100, Chris Zimman <czimman@bloomberg.com> wrote:

[Interrupt every 12us]

> Not to get of topic, but are you running eCos w/o the scheduler?  Because if
> you're not, I don't see how you are going to be able to keep up with the time
> interval that you need.

I use the scheduler...

> That said, I would suggest just pointing the FIQ vector directly, and
> managing your own stack.  You could just carve out a piece of memory for
> yourself (many ways to do this, depending on your application) and use that.

Yes - this was my idea too. Just beginnig a pice of assembler code at the
FIQ adress. (Even without a jump because it is at the end of the vector table)
Since the FIQ has 8 banked registers I fortunately do not even need a stack.

I'd like to place the ring-buffer into the fast onchip sram.
Can I just define some symbols in the linker script for that purpose? Or
can I tell the assembler to generate some symbols in a special section
like

.section ".sram_data"
_adc_buffer:
	.rept 64
	.long 0
	.endr
_adc_buffer_start:
	.long 0
_adc_buffer_end:
	.long 0


Greetings,
 Martin L.