62.144 GMAC Screening Type 2 Compare Word 1 Register x

Name: GMAC_ST2CW1Rx
Offset: 0x0704 + x*0x08 [x=0..23]
Reset: 0x00000000
Property: Read/Write

Bit 3130292827262524 
          
Access  
Reset  
Bit 2322212019181716 
          
Access  
Reset  
Bit 15141312111098 
       DISMASKOFFSSTRT[1] 
Access R/WR/W 
Reset 00 
Bit 76543210 
 OFFSSTRT[0]OFFSVAL[6:0] 
Access R/WR/WR/WR/WR/WR/WR/WR/W 
Reset 00000000 

Bit 9 – DISMASK Disable Mask

Controls whether GMAC_ST2CW0R contains a 2-byte compare value with a 2-byte mask value or a 4-byte compare value.
ValueDescription
0 GMAC_ST2CW0Rx contains a 2-byte compare value with a 2-byte mask value.
1 GMAC_ST2CW0Rx contains a 4-byte compare value.

Bits 8:7 – OFFSSTRT[1:0] Ethernet Frame Offset Start

ValueNameDescription
0 FRAMESTART

Offset from the start of the frame

1 ETHERTYPE

Offset from the byte after the EtherType field

2 IP

Offset from the byte after the IP header field

3 TCP_UDP

Offset from the byte after the TCP/UDP header field

Bits 6:0 – OFFSVAL[6:0] Offset Value in Bytes

The value of OFFSVAL ranges from 0 to 127 bytes, and is counted from either the start of the frame, the byte after the EtherType field (last EtherType in the header if the frame is VLAN tagged), the byte after the IP header (IPv4 or IPv6) or the byte after the TCP/UDP header.