Texas Instruments TMS320TCI6486 manual Promiscuous Receive Mode, Receive Frame Treatment Summary

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2.11.8Promiscuous 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.

SPRUEF8F –March 2006 –Revised November 2010	C6472/TCI6486 EMAC/MDIO 61
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