User guide

Filter Details frame types and length

 We have a filter to detect the type of the frame

− ARP

− IP which is divided in

1. ICMP internet control message protocol

2. IGMP internet group management protocol

3. UDP/IP user datagram protocol

TCP/IP Transmission control protocol

 For IP we can test if the announced total length is matching the real frame length

with revisions until 1.7 we did this length test also on ARP, this failed on some systems using a special

driver from Intel, that driver did not extend a ARP frame to the minimum of 64 bytes on the wire, it

extended to 108 bytes (or so), and the GMACII rejected that ARP

 All these filters can be combined or disabled, please see the ifi_gmac_regs.h for details,

in the reference software you can find a subroutine which prints the actual setting