Arty Z7 lwip echo server

[Charles Hill]

I have a problem with the Arty Z7 board and the lwip echo server provided with SDK 2018.2.  I've determined the Arty never responds to an ARP sent over the Ethernet.  When manually setting the ARP to IP address routing, the TCP level doesn't respond either.  The lwip echo server sets the MAC address to 00:0a:35:00:01:02 but in the Arty Z7 reference manual it says "On an Ethernet network each node needs a unique MAC address. To this end, the one-time-programmable (OTP) region of the Quad-SPI flash has been programmed at the factory with a 48-bit globally unique EUI-48/64TM compatible identifier."  The link to instructions on how to read the OTP gives a 404 error.   The activity light on the Ethernet Phy is flashing.  How do I verify the MAC address which is programmed?

 

[JColvin]

Hi @Charles Hill,

I have asked some other engineers for their input on this. The MAC address would be stored in the Quad-SPI Flash OTP region (which you already mentioned) which for your board may be a Spansion S25FL128SAGMFI00, though there are some other potential loads as listed in it's Reference Manual here: https://reference.digilentinc.com/reference/programmable-logic/arty-z7/reference-manual#quad_spi_flash. The datasheet for the Spansion chip I mentioned is available as a direct download from Cypress here: https://www.cypress.com/file/448601/download.

Thanks,
JColvin