LAN91C100-FD SMSC [SMSC Corporation], LAN91C100-FD Datasheet - Page 38

• Manufacturer Part Number: LAN91C100-FD
• Description: FEAST FAST ETHERNET CONTROLLER WITH FULL DUPLEX CAPABILITY
• Manufacturer: SMSC [SMSC Corporation]

BANK3
BANK 3
Rev. 10/14/2002
0 THROUGH 7
HIGH
BYTE
BYTE
LOW
BYTE
BYTE
BYTE
BYTE
BYTE
BYTE
BYTE
BYTE
HIGH
HIGH
HIGH
HIGH
LOW
LOW
LOW
LOW
OFFSET
OFFSET
The 64 bit multicast table is used for group address filtering. The hash value is defined as the six most
significant bits of the CRC of the destination addresses. The three msb's determine the register to be used
(MT0-MT7), while the other three determine the bit within the register.
If the appropriate bit in the table is set, the packet is received.
If the ALMUL bit in the RCR register is set, all multicast addresses are received regardless of the multicast
table values.
Hashing is only a partial group addressing filtering scheme, but being the hash value available as part of
the receive status word, the receive routine can reduce the search time significantly. With the proper
memory structure, the search is limited to comparing only the multicast addresses that have the actual
hash value in question.
8
FLTST
0
0
0
0
0
0
0
0
0
0
MANAGEMENT INTERFACE
CRS100
MSK_
MULTICAST TABLE
0
0
0
0
0
0
0
0
0
0
NAME
NAME
PRELIMINARY
0
0
0
0
0
0
0
0
1
1
MULTICAST TABLE 0
MULTICAST TABLE 1
MULTICAST TABLE 2
MULTICAST TABLE 3
MULTICAST TABLE 4
MULTICAST TABLE 5
MULTICAST TABLE 6
MULTICAST TABLE 7
Page 38
0
0
0
0
0
0
0
0
1
1
MDOE
READ/WRITE
READ/WRITE
0
0
0
0
0
0
0
0
0
0
FEAST Fast Ethernet Controller with Full Duplex Capability
TYPE
TYPE
MCLK
0
0
0
0
0
0
0
0
0
0
SMSC DS – LAN91C100FD Rev. D
MDI Pin
MDI
0
0
0
0
0
0
0
0
1
SYMBOL
SYMBOL
MGMT
MT
MDO
0
0
0
0
0
0
0
0
1
0