NH82801DB S L8DE Intel, NH82801DB S L8DE Datasheet - Page 270

• Manufacturer Part Number: NH82801DB S L8DE
• Manufacturer: Intel

Specifications of NH82801DB S L8DE

• Lead Free Status / RoHS Status: Compliant

LAN Controller Registers (B1:D8:F0)
7.2.9
270
Flow Control Register
Offset Address:
Default Value:
15:13
Bit
7:3
2:0
12
11
10
9
8
Reserved
FC Paused Low — RO.
0 = Cleared when the FC timer reaches zero, or a Pause frame is received.
1 = Set when the LAN controller receives a Pause Low command with a value greater than zero.
FC Paused — RO.
0 = Cleared when the FC timer reaches zero.
1 = Set when the LAN controller receives a Pause command regardless of its cause (FIFO
FC Full — RO.
0 = Cleared when the FC timer reaches zero.
1 = Set when the LAN controller sends a Pause command with a value greater than zero.
Xoff — R/W (special). This bit should only be used if the LAN controller is configured to operate with
IEEE frame-based flow control.
0 = This bit can only be cleared by writing a 1 to the Xon bit (bit 8 in this register).
1 = Writing a 1 to this bit forces the Xoff request to 1 and causes the LAN controller to behave as if
Xon — WO. This bit should only be used if the LAN controller is configured to operate with IEEE
frame-based flow control.
0 = This bit always returns 0 on reads.
1 = Writing a 1 to this bit resets the Xoff request to the LAN controller, clearing bit 9 in this register.
Reserved
Flow Control Threshold — R/W. The LAN controller can generate a Flow Control Pause frame
when its Receive FIFO is almost full. The value programmed into this field determines the number of
bytes still available in the Receive FIFO when the Pause frame is generated.
Bits 2:0
000
001
010
011
100
101
110
111
reaching Flow Control Threshold, fetching a Receive Frame Descriptor with its Flow Control
Pause bit set, or software writing a 1 to the Xoff bit).
the FIFO extender is full. This bit will also be set to 1 when an Xoff request due to an “RFD
Xoff” bit.
19
h
Free Bytes
in Receive FIFO
0.50 KB
1.00 KB
1.25 KB
1.50 KB
1.75 KB
2.00 KB
2.25 KB
2.50 KB
–
1Ah
Comment
Fast system (recommended default)
Slow system
Description
Attribute:
Size:
Intel
RO, R/W (special)
16 bits
®
82801DB ICH4 Datasheet