[lwip-users] [lwip] lwIP in a non-OS environment

[Alexander Groß]

Hello everybody,

I have some questions concering the usage of the lwIP-stack in an
environment where no operating system could be used. We would like to
integrate TCP/IP support to our PLC solutions, so the whole applications is
very time-critical.
I didn't find much about lwIP w/o OS on raw API in the documentation I hope
you can help me to reach a decision if I could use lwIP.

For developement purposes I'll use the Keil MCB-167NET Board. It is equipped
with an Infineon 167 and the Crystal CS8900 ethernet controller. We can't
support an OS since we just want to build a network layer that can be used
with any of our existing applications (which are not only PLCs). The network
layer has to be called cyclic from the application to make sure that CPU
time is shared between application and network layer. It is also
unacceptable for us to wait for some kind of processing (i.e. semaphores)
since we have time-critical applications with a maximum time per cyle (i.e.
PLC).

I would have to implement a state machine to hande the network layer, which
is no problem.

There are some missing information:
- Does lwIP support an environment decribed above (no OS, no wait timers)?
- If I use the raw API, is there some "intelligence", like TCP fast
retransmit/recovery, implemented or will I have to set up my own algorithms?
- How can I give lwIP CPU cycles that it can process enqueued packets?

I hope you can clear my view!
Thanks in advance.

Regards,

Alex

_________________________________________

Alexander Groß
Student in Computer Sciences

SYS TEC electronic GmbH
August-Bebel-Straße 29
07973 Greiz
Germany

Phone: +49 36 61 / 62 79 - 0
Fax: +49 36 61 / 62 79 - 48
www: http://www.systec-electronic.de
e-mail: address@hidden
_________________________________________

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