Filter
Top Products
www.ti.com
EMAC Functional Architecture
2.11.8 Promiscuous Receive Mode
When the promiscuous receive mode is enabled by setting the RXCAFEN bit in the RXMBPENABLE
register, non-address matching frames that would normally be filtered are transferred to the promiscuous
channel. Address matching frames that would normally be filtered due to errors are transferred to the
address match channel when the RXCAFEN and RXCEFEN bits are set. Address matching frames with
the filter bit set (MATCHFILT = 0) are always filtered regardless of the RXCAFEN and RXCEFEN bit
setting. A frame is considered to be an address matching frame only if it is enabled to be received on a
unicast, multicast, or broadcast channel. Frames received to disabled unicast, multicast, or broadcast
channels are considered non-address matching.
MAC control frames address match only if the RXCMFEN bit is set. RXCEFEN and RXCSFEN determine
whether error frames are transferred to memory or not, but they do not determine whether error frames
are address matching or not. Short frames are a special type of error frames.
A single channel is selected as the promiscuous channel by the RXPROMCH field in the RXMBPENABLE
register. The promiscuous receive mode is enabled by the RXCMFEN, RXCEFEN, RXCSFEN, and
RXCAFEN bits in RXMBPENABLE. Table 14 shows the effects of the promiscuous enable bits. Proper
frames are frames that are between 64 and RXMAXLEN bytes in length inclusive and contain no code,
align, or CRC errors.
Table 14. Receive Frame Treatment Summary
Address RXMBPENABLE Bits
Match
RXCAFEN RXCEFEN RXCMFEN RXCSFEN Frame Treatment
0 0 X X X No frames transferred.
0 1 0 0 0 Proper frames transferred to promiscuous channel.
0 1 0 0 1 Proper/undersized data frames transferred to promiscuous
channel.
0 1 0 1 0 Proper data and control frames transferred to promiscuous
channel.
0 1 0 1 1 Proper/undersized data and control frames transferred to
promiscuous channel.
0 1 1 0 0 Proper/oversize/jabber/code/align/CRC data frames transferred
to promiscuous channel. No control or undersized/fragment
frames are transferred.
0 1 1 0 1 Proper/undersized/fragment/oversize/jabber/code/align/CRC
data frames transferred to promiscuous channel. No control
frames are transferred.
0 1 1 1 0 Proper/oversize/jabber/code/align/CRC data and control frames
transferred to promiscuous channel. No undersized frames are
transferred.
0 1 1 1 1 All non-address matching frames with and without errors
transferred to promiscuous channel.
1 X 0 0 0 Proper data frames transferred to address match channel.
1 X 0 0 1 Proper/undersized data frames transferred to address match
channel.
1 X 0 1 0 Proper data and control frames transferred to address match
channel.
1 X 0 1 1 Proper/undersized data and control frames transferred to
address match channel.
1 X 1 0 0 Proper/oversize/jabber/code/align/CRC data frames transferred
to address match channel. No control or undersized frames are
transferred.
1 X 1 0 1 Proper/oversize/jabber/fragment/undersized/code/align/CRC
data frames transferred to address match channel. No control
frames are transferred.
61
SPRUEF8F–March 2006–Revised November 2010 C6472/TCI6486 EMAC/MDIO
Submit Documentation Feedback
Copyright © 2006–2010, Texas Instruments Incorporated