Packet Filtering
BCM5718 Programmer’s Guide
Broadcom
®
January 29, 2016 • 5718-PG108-R
Page 138
for(k = 0; k < 8; k++)
{
Tmp = Reg & 0x01;
Reg >>= 1;
if(Tmp)
{
Reg ^= 0xedb88320;
}
}
}
return ~Reg;
}
Promiscuous Mode Setup/Configuration
The host software may enable promiscuous mode by setting the Promiscous_Mode bit (bit 8) of the
Receive_MAC_Mode register (offset 0x468). The Promiscous_Mode bit defaults to disabled after reset, and
host software must explicitly set this bit for promiscuous mode. In promiscuous mode of operation, the Ethernet
controller accepts all incoming frames that are not filtered by the active receive rules regardless of the
destination MAC address. In other words, the Ethernet controller operating in promiscuous mode ignores
multicast and MAC address filtering (
“Multicast Hash Table Setup/Configuration” on page 135
Address Setup/Configuration” on page 135
), but applies Receive Rules.
Broadcast Setup/Configuration
The host software may configure the Ethernet controller to discard the received broadcast frames by using two
receive rules as defined below. The Ethernet controller parses all incoming frames according to these receive
rules and discards those frames that have a broadcast destination address (see
Frame Classification” on page 95
for more details on setting up the receive rules).
The following is a sample of the two receive rules for discarding broadcast frames.
Rule1 Control: 0xc2000000
Rule1 Mask/Value: 0xffffffff
Rule2 Control: 0x86000004
Rule2 Mask/Value: 0xffffffff