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Re: Some newbie questions
- To: Andreas Hofer <ho at dsa-ac dot de>
- Subject: Re: [ECOS] Some newbie questions
- From: Andrew Lunn <andrew dot lunn at ascom dot ch>
- Date: Tue, 26 Jun 2001 13:55:07 +0200
- Cc: ecos-discuss at sources dot redhat dot com
- References: <001101c0fe33$751261a0$12191dac@PCHO2>
> We have developed a SA1110 based board used to perform CAN bus
> communication. The CAN controller in use is the Philips SJA1000. Some
> communication partners on the CAN bus expect our board to respond within
> a guaranteed time limit of 40 Microseconds. Guaranteed means hard
> realtime, right? Can eCos meet these requirements?
eCos is not a hard real time OS. There is no deadline scheduling, no
guarantees. Everything it best effort. You do have priorities per
thread, so you can priorities your CAN bus handler above everything
else to improve is responce time.
Whats your definition of responce time? The time taken for an ISR to
run? The time before a thread starts to run? I have an application
also on an SA1110 processor which requires that the schedular is not
disabled for longer than 200us. eCos can do that without a problem on
our target hardware.
> How difficult do
> you expect the adaption of eCos to a new SA1110 based board like ours to
> be?
How different is it to the other SA1110 platforms that are supported?
Does it use the same flash chips? Same memory layout? etc. The more
similar it is, the less work involved.
Andrew