zain aftab

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10 years ago.

lpc1768 ethernet

Hi all, I created a test program on lpc1768 for ethernetinterface, i have not tested it yet because dont have any ethernet cable now

The thing i want to ask is that my application is using 39% of ram, because etherent interface consumes that much library.

Has any one tested any etherent application on lpc1768 ? i have worked with K64F it works fine with it, but that board has some software limitation that is why i switched to lpc1768

1 Answer

Stefano Bianciotto
10 years ago.

How much was the RAM used on the FRDM-K64F? Consider that the FRM-K64F has 256 kB of RAM while the LPC1768 has only 32 kB of RAM: if on the LPC1768 your program uses the 39 % (i.e. 0.39 * 32 kB = 12.5 kB) on the FRDM-K64F this corresponds only to 12.5 kB / 256 kB * 100 = 4.9 %. Just out of curiosity, what are the software limitations that you found on the FRDM-K64F board?

K64F board is not allowing to declare big arrays or multiple threads, you can search this forum as well. I tried my application on kl25z as well using cc3000 library which just have 16KB of ram but it runs perfectly fine on it. Because cc3000 library consumes very less memory.

posted by zain aftab 28 Nov 2014

The LPC1768 has another memory bank it can use for ethernet, which is why the display amount of RAM is not very useful when running ethernet applications.

Outside that you are right, the K64F has alot more RAM. IIRC he used 20% or so in the end of his RAM, so I didn't really know what was the issue there. And I don't understand the question here: Of course people have used ethernet on the LPC1768.

posted by Erik - 28 Nov 2014

I have been trying on K64F from last couple of weeks and I am facing the similar kind of thing. https://developer.mbed.org/questions/3329/Internal-Size-Limit-K64F-mbed-mbed-rtos-/

My program also consumes 22% of ram and 7% of flash but it crashes if i increase the size of array. even minor changes cause the program to crash.

It is weird but i think there is some software bug in K64F libraries

posted by zain aftab 28 Nov 2014