Our company uses w5200 in our products. I need to receive RAW Ethernet frames. No IP layer. Just to capture RAW frames.
While testing I ran into the issue with Erratum 3. I test sending 60 bytes ARP frame to w5200. While receiving it I read the packet info as 62 or 63 instead of 60. I don’t see any dummy bytes appended until the next packet info. After 60 bytes, the next packet info is available.
Below is the quote from erratum 3 for w5200
- When the received packet size is larger than the actual received packet size.
The received MACRAW data format is shown in the figure below. The PACKET-INFO (the
byte size of data packet) can also be larger than the actual packet size in this
phenomenon. Therefore, the Dummy data is inserted from the actual packet size to the
The problem with the provided solution is I don’t use any ip layer, I just want to capture the raw frames which includes ARP packets. Since no dummy bytes are getting appended and the packet info is incorrect, I don’t know how much bytes to read.
My question is, why am I not seeing dummy byte getting appended? This behavior is not as expected in the errata! What is the solution to receive ARP frame/ any other frame without using IP information? Is it possible?