Intel IXF1104 FC Enable $ PortIndex +, FC Back Pressure Length $ PortIndex +, TX Hdfc, TX Fdfc

Intel® IXF1104 4-Port Gigabit Ethernet Media Access Controller

Table 84. FC Enable ($ Port_Index + 0x12)

Bit	Name	Description	Type1	Default
Register Description: Indicates which flow control mode is used for the RX and TX MAC.				0x00000007
31:3	Reserved	Reserved	R	0x00000000
		When TX HDFC is enabled (half-duplex mode
		only), the MAC generates deliberate collisions on
2	TX HDFC	incoming packets when the RX FIFO occupancy	R/W	1
		crosses the High Watermark (flow control).
		0 = Disable TX half-duplex flow control
		1 = Enable TX half-duplex flow control
		0 = Disable TX full-duplex flow control [the MAC
		will not generate internally any flow control
		frames based on the RX FIFO watermarks or
		the Transmit Pause Control interface	R/W	1
1	TX FDFC	1 = Enable TX full-duplex flow control [enables
		the MAC to send flow control frames to the
		link partner based on the RX FIFO
		programmable watermarks or the Transmit
		Pause Control interface]
		0 = Disable RX full-duplex flow control [the MAC
		will not respond to flow control frames sent to
		it by the link partner]
0	RX FDFC	1 = Enable RX full-duplex flow control [MAC will	R/W	1
		respond to flow control frames sent by the link
		partner and will stop packet transmission for
		the time specified in the flow control frame]

1. RO = Read Only, No clear on Read; R = Read, Clear on Read; W = Write only; R/W = Read/Write, No clear; R/W/C = Read/Write, Clear on Write

Table 85. FC Back Pressure Length ($ Port_Index + 0x13)

Name	Description	Address	Type1	Default
	This register sets number the byte cycles
	for which the collision has to be applied.
	The 6-bit configuration holds the value in
FC Back Pressure	bytes, which applies to the minimum	Port Add +
	length/duration of back pressure in half-		R/W	0x0000000C
Length		0x13
	duplex mode. Flow control in the receive
	path is executed by deliberately colliding
	the incoming packets in half-duplex mode.
	Register bits 5:0 are used alone.

1. RO = Read Only, No clear on Read; R = Read, Clear on Read; W = Write only; R/W = Read/Write, No clear; R/W/C = Read/Write, Clear on Write

Datasheet 168

Document Number: 278757

Revision Number: 009

Revision Date: 27-Oct-2005