Two Port 10/100 Managed Ethernet Switch with 16-Bit Non-PCI CPU Interface

Datasheet

14.3.4Host MAC Multicast Hash Table High Register (HMAC_HASHH)

Offset:

4h

Size:

32 bits

The 64-bit Multicast table is used for group address filtering. For hash filtering, the contents of the destination address in the incoming frame is used to index the contents of the Hash table. The most significant bit determines the register to be used (Hi/Low), while the other five bits determine the bit within the register. A value of 00000 selects Bit 0 of the Multicast Hash Table Lo register and a value of 11111 selects the Bit 31 of the Multicast Hash Table Hi register.

If the corresponding bit is 1, then the multicast frame is accepted. Otherwise, it is rejected. If the “Pass All Multicast” (MCPAS) bit of the Host MAC Control Register (HMAC_CR) is set, then all multicast frames are accepted regardless of the multicast hash values.

The Multicast Hash Table High register contains the higher 32 bits of the hash table and the Multicast Hash Table Low register contains the lower 32 bits of the hash table. Refer to Section 9.4, "Address Filtering," on page 115 for more information on address filtering.

This table determines if the Host MAC accepts the packets from the switch fabric. The switch fabric address table and configuration determine the packets that get sent to the Host MAC.

BITS

DESCRIPTION

TYPE

DEFAULT

 

 

 

 

31:0

Upper 32-bits of the 64-bit Hash Table

R/W

00000000h

 

 

 

 

SMSC LAN9311/LAN9311i

277

Revision 1.4 (08-19-08)

 

DATASHEET