# AT91SAM7X256 and DP83848C

**URL:** <https://forums.freertos.org/t/at91sam7x256-and-dp83848c/5669>\
**Category:** Kernel\
**Created:** [August 29, 2008, 12:27pm UTC](https://forums.freertos.org/t/at91sam7x256-and-dp83848c/5669 "2008-08-29T12:27:43Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![system](https://d2v6vdsk2p900z.cloudfront.net/original/1X/7fc8fdb729c645aab5b20282bbe34e57cb407be6.jpeg) [@system](https://forums.freertos.org/u/system)\
**Post date:** [August 29, 2008, 12:27pm UTC](https://forums.freertos.org/t/at91sam7x256-and-dp83848c/5669/1 "2008-08-29T12:27:43Z")

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**[thomahauc](https://sourceforge.net/u/thomahauc/)** wrote on [Friday, August 29, 2008](https://sourceforge.net/p/freertos/discussion/382005/thread/fa789bc6/#6432):

Hi,

I am new on this forum and on FreeRTOS.

I try to set up the SAM7 and the PHY to work correctly together but something goes wrong. My try is based on ‘lwIP\_Demo\_Rowley\_ARM7’ demo project.

The SAM7 got ARP packets and for each packet it produces the reply packet. The packets never reach the LAN.

I would like to know if someone has working code to handle the DP83848C with a AT91SAM7X256.

Thanks you in advance.

Thoma

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<div class="post-metadata">

**Author:** ![system](https://d2v6vdsk2p900z.cloudfront.net/original/1X/7fc8fdb729c645aab5b20282bbe34e57cb407be6.jpeg) [@system](https://forums.freertos.org/u/system)\
**Post date:** [August 29, 2008, 2:25pm UTC](https://forums.freertos.org/t/at91sam7x256-and-dp83848c/5669/2 "2008-08-29T14:25:58Z")

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**[davedoors](https://sourceforge.net/u/davedoors/)** wrote on [Friday, August 29, 2008](https://sourceforge.net/p/freertos/discussion/382005/thread/fa789bc6/#6432/f927):

You could try looking in the files section of the SAM7 Yahoo group. You might get lucky and find an example for the same phy.

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<div class="post-metadata">

**Author:** ![system](https://d2v6vdsk2p900z.cloudfront.net/original/1X/7fc8fdb729c645aab5b20282bbe34e57cb407be6.jpeg) [@system](https://forums.freertos.org/u/system)\
**Post date:** [August 29, 2008, 5:46pm UTC](https://forums.freertos.org/t/at91sam7x256-and-dp83848c/5669/3 "2008-08-29T17:46:20Z")

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**[david\_farrell](https://sourceforge.net/u/david_farrell/)** wrote on [Friday, August 29, 2008](https://sourceforge.net/p/freertos/discussion/382005/thread/fa789bc6/#6432/6bce):

The obvious one, did you change the IP address to be compatible with your network?  
My problem was with an Olimex SAM7-EX256 board where the PHY address was not correct.&nbsp; You have to carefully review the PHY documentation to see what the default address is and how it is reprogrammed.&nbsp; The FreeRTOS example was not compatible with the Olimex design PHY (KSZ8721BL).&nbsp; If you are sure you received ARP packets, I doubt this is your problem.