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Re: programming in FLASH hamper real time operation??
- From: Andrew Lunn <andrew at lunn dot ch>
- To: abhishek srivastava <just_abhi22 at yahoo dot co dot in>
- Cc: ecos-discuss at sourceware dot org
- Date: Fri, 28 Nov 2008 09:01:26 +0100
- Subject: Re: [ECOS] programming in FLASH hamper real time operation??
- References: <434948.72613.qm@web94601.mail.in2.yahoo.com>
On Fri, Nov 28, 2008 at 11:19:15AM +0530, abhishek srivastava wrote:
> sir,
> i got a doubt when i saw larmour's post (Re: Support for LPC2XXX IAP interface) in ecos-patches!
> i am trying to port ecos onto LPC2148 so as to do some realtime application with that.
> as this board doesnot have sufficient RAM, would porting ecos to ROM will hamper the real time property of ecos??
ROM is generally slower than RAM. So running from ROM might slow your
execution speed down a little. However it is deterministic. So the
system will still be as real time, just slower.
The problem comes when you start writing to FLASH while running from
FLASH. Flash controllers don't allow this. You have to stop what you
are doing, and only perform writes to FLASH. You cannot do anything
else. So you loose your real time properties.
So if you can avoid writing to FLASH you should not have to worry.
Andrew
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