Nxp Semiconductors UM10237 User Manual

UM10237_2

© NXP B.V. 2008. All rights reserved.

Ethernet MAC will stop writing further data in the frame to memory; the FailFilter bit in the 
status word of the frame will be set to indicate that the software device driver can discard 
the frame immediately.

 

Generic filtering based on the type of frame (unicast, multicast or broadcast) can be 
programmed using the AcceptUnicastEn, AcceptMulticastEn, or AcceptBroadcastEn bits 
of the RxFilterCtrl register. Setting the AcceptUnicast, AcceptMulticast, and 
AcceptBroadcast bits causes all frames of types unicast, multicast and broadcast, 
respectively, to be accepted, ignoring the Ethernet destination address in the frame. To 
program promiscuous mode, i.e. to accept all frames, set all 3 bits to 1.

When a frame with a unicast destination address is received, a perfect filter compares the 
destination address with the 6 byte station address programmed in the station address 
registers SA0, SA1, SA2. If the AcceptPerfectEn bit in the RxFilterCtrl register is set to 1, 
and the address matches, the frame is accepted.

IMPERFECT

HASH

FILTER

AcceptUnicastEn

AcceptMulticastEn

AcceptMulticastHashEn

AcceptUnicastHashEn

HashFilter

PERFECT
ADDRESS

FILTER

packet

CRC

OK?

HF

Re

a

d

y

HF

M

a

tc

h

PA

R

e

a

d

y

PA

M

a

tc

h

RxAbort

FReady

FMatch

RxFilterEnWoL

RxFilterWoL

StationAddress

AcceptPerfectEn