High Performance Two Port 10/100 Managed Ethernet Switch with 32-Bit Non-PCI CPU Interface

Datasheet

BITS

DESCRIPTION

TYPE

DEFAULT

 

 

 

 

16

Pass Bad Frames (PASSBAD)

R/W

0b

 

When set, all incoming frames that passed address filtering are received,

 

 

 

including runt frames and collided frames. Refer to Section 9.4, "Address

 

 

 

Filtering," on page 114 for additional information.

 

 

 

 

 

 

15

Hash Only Filtering mode (HO)

R/W

0b

 

When set, the address check Function operates in the Imperfect address

 

 

 

filtering mode for both physical and multicast addresses. Refer to Section

 

 

 

9.4.2, "Hash Only Filtering," on page 115 for additional information.

 

 

 

 

 

 

14

RESERVED

RO

-

 

 

 

 

13

Hash/Perfect Filtering Mode (HPFILT)

R/W

0b

 

When cleared (0), the LAN9312 will implement a perfect address filter on

 

 

 

incoming frames according the address specified in the Host MAC address

 

 

 

registers (Host MAC Address High Register (HMAC_ADDRH) and Host

 

 

 

MAC Address Low Register (HMAC_ADDRL)).

 

 

 

When set (1), the address check function performs imperfect address

 

 

 

filtering of multicast incoming frames according to the hash table specified

 

 

 

in the multicast hash table register. If the Hash Only Filtering mode (HO) bit

 

 

 

15 is set, then the physical (IA) addresses are also imperfect filtered. If the

 

 

 

Hash Only Filtering mode (HO) bit is cleared, then the IA addresses are

 

 

 

perfect address filtered according to the MAC Address register Refer to

 

 

 

Section 9.4.3, "Hash Perfect Filtering," on page 115 for additional

 

 

 

information.

 

 

 

 

 

 

12

RESERVED

RO

-

 

 

 

 

11

Disable Broadcast Frames (BCAST)

R/W

0b

 

When set, disables the reception of broadcast frames. When cleared,

 

 

 

forwards all broadcast frames to the application.

 

 

 

Note: When wake-up frame detection is enabled via the WUEN bit of the

 

 

 

Host MAC Wake-up Control and Status Register (HMAC_WUCSR),

 

 

 

a broadcast wake-up frame will wake-up the device despite the

 

 

 

state of this bit.

 

 

 

 

 

 

10

Disable Retry (DISRTY)

R/W

0b

 

When set, the Host MAC attempts only one transmission. When a collision

 

 

 

is seen on the bus, the Host MAC ignores the current frame and goes to the

 

 

 

next frame and a retry error is reported in the Transmit status. When reset,

 

 

 

the Host MAC attempts 16 transmissions before signaling a retry error.

 

 

 

 

 

 

9

RESERVED

RO

-

 

 

 

 

8

Automatic Pad Stripping (PADSTR)

R/W

0b

 

When set, the Host MAC strips the pad field on all incoming frames, if the

 

 

 

length field is less than 46 bytes. The FCS field is also stripped, since it is

 

 

 

computed at the transmitting station based on the data and pad field

 

 

 

characters, and is invalid for a received frame that has had the pad

 

 

 

characters stripped. Receive frames with a 46-byte or greater length field

 

 

 

are passed to the application unmodified (FCS is not stripped). When

 

 

 

cleared, the Host MAC passes all incoming frames to the host unmodified.

 

 

 

 

 

 

SMSC LAN9312

271

Revision 1.4 (08-19-08)

 

DATASHEET