2007-01-21 11:34:53

by Kevin D. Kissell

[permalink] [raw]
Subject: Re: Running Linux on FPGA

> > The overhead of timer interrupts at this low clockrate is significant
> > so I recommend to minimize the timer interrupt rate as far as possible.
> > This is really a tradeoff between latency and overhead and matters
> > much less on hardcores which run at hundreds of MHz. For power sensitive
> > applications lowering the interrupt rate can also help. And that's alredy
> > pretty much what you need to know, that is a 10ms timer is fine.
> >
>
> I have worked with FPGA Linux system which is reconfigurable
> on-the-fly by the 200Mhz ARM9 CPU running Debian Linux, Altera Cyclone
> II FPGA is included on my TS-7300 board. Advantage is, Altera FPGA and
> a dedicated high-speed bus between the CPU and FPGA provides a good
> design scope to provide many solutions.

What's your point here? A 200MHz hard ore won't see the issues
under discussion. We're talking about systems where the CPU itself
is "soft" and implemented in an FPGA.

Regards,

Kevin K.