Xilinx UG144 manual 6Flow Control Configuration Word Bit Default Description

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Using the Optional Management Interface

Table 8-5:Transmitter Configuration Word (Continued)

R

Bit	Default	Description
	Value
29	0	In-band FCS Enable When this bit is ‘1,’ the MAC
		transmitter will expect the FCS field to be passed in by the
		client. When this bit is ‘0,’ the MAC transmitter will
		append padding as required, compute the FCS and
		append it to the frame.
30	0	Jumbo Frame Enable When this bit is set to ‘1,’ the MAC
		transmitter will send frames that are greater than the
		specified IEEE 802.3-2005maximum legal length. When
		this bit is ‘0,’ the MAC will only send frames up to the
		specified maximum.
31	0	Reset When set to ‘1,’ the transmitter will be reset. The bit
		will then automatically revert to ‘0.’ This reset will also set
		all of the transmitter configuration registers to their default
		values.

Flow Control Configuration

Table 8-6lists the register contents for the Flow Control Configuration Word.

Table 8-6:Flow Control Configuration Word

Bit	Default	Description
	Value
28-0	n/a	Reserved
29	1	Flow Control Enable (RX) When this bit is ‘1,’ received
		flow control frames will inhibit the transmitter operation.
		When this bit is ‘0,’ received flow control frames will
		always be passed up to the client.
30	1	Flow Control Enable (TX) When this bit is ‘1,’ asserting the
		PAUSE_REQ signal will send a flow control frame out
		from the transmitter. When this bit is ‘0,’ asserting the
		PAUSE_REQ signal has no effect.
31	n/a	Reserved

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UG144 April 24, 2009