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Re: ROMRAM application runs much slower than RAM
- From: Gary Thomas <gary at mlbassoc dot com>
- To: Harshit Suri <h dot r dot suri at gmail dot com>
- Cc: eCos Discussion <ecos-discuss at ecos dot sourceware dot org>
- Date: Sun, 06 Feb 2005 05:29:33 -0700
- Subject: Re: [ECOS] ROMRAM application runs much slower than RAM
- Organization: MLB Associates
- References: <a2ced48c05020601427ee79ea@mail.gmail.com>
On Sun, 2005-02-06 at 01:42 -0800, Harshit Suri wrote:
> Hi
> I've built an application code both in ROMRAM startup and RAM startup mode.
> The code blinks LEDs.
>
> The ROMRAM application runs *significantly* slower than the RAM
> version. The time between LEDs blinks is much longer in ROMRAM. I've
> generated the delays using 'for' loops like so:
>
> while(1)
> {
> LEDs ON;
> for (delay = 0 ; delay <100000;delay++);
> LEDs OFF;
> for (delay = 0 ; delay <100000;delay++);
> }
>
> All parameters like clock frequency and RTC settings are same in both.
>
> This puzzles me. Both startup modes finally run from RAM.
>
> Then why this disparity in speeds?
> thanks
It's hard to tell with so few details.
What's the target platform?
Are you sure that caches are enabled in the ROMRAM configuration?
--
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Gary Thomas | Consulting for the
MLB Associates | Embedded world
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