82583V Datasheet, PDF (232/374 Pages) Intel Corporation – Intel® 82583V GbE Controller

82583V GbE Controller—Driver Programing Interface
Table 50.
Field
Reserved
DPF
PMCF
Reserved
BSEX
SECRC
FLXBUF
Reserved
Bit(s)
21
22
23
24
25
26
30:27
31
Initial
Value
0b
0b
0b
0b
0b
0b
0x0
0b
Description
Reserved
Should be written with 0b to ensure future compatibility.
Discard Pause Frames
Any valid pause frame is discarded regardless of whether it matches
any of the filter registers.
0b = Incoming frames subject to filter comparison.
1b = Incoming pause frames ignored even if they match filter
registers.
Pass MAC Control Frames
0b = Do not (specially) pass MAC control frames.
1b = Pass any MAC control frame (type field value of 0x8808) that
does not contain the pause opcode of 0x0001.
Reserved
Should be written with 0b to ensure future compatibility.
Buffer Size Extension
Modifies the buffer size indication (BSIZE). When set to 1b, the
original BSIZE values are multiplied by 16.
Strip Ethernet CRC from incoming packet.
Do not DMA to host memory.
Determines a flexible buffer size. When this field is 0x0000, the buffer
size is determined by BSIZE. If this field is different from 0x0000, the
receive buffer size is the number represented in KB. For example,
0x0001 = 1 KB (1024 bytes).
Reserved
Should be written with 0b to ensure future compatibility.
Hardware discards long packets if LPE is 0b. A long packet is one longer than 1522
bytes. Note that the 82583V does not support setting LPE to 1b.
RDMTS[1,0] determines the threshold value for free receive descriptors according to
the following table:
RDMTS Values
RDMTS
00b
01b
10b
11b
Free Buffer Threshold
1/2
1/4
1/8
Reserved
BSIZE controls the size of the receive buffers and permits software to trade-off
descriptor performance versus required storage space. Buffers that are 2048 bytes
require only one descriptor per receive packet maximizing descriptor efficiency. Buffers
that are 256 bytes maximize memory efficiency at a cost of multiple descriptors for
packets longer than 256 bytes.
Three bits control the VLAN filter table. The first determines whether the table
participates in the packet acceptance criteria. The next two are used to decide whether
the CFI bit found in the 802.1Q packet should be used as part of the acceptance
criteria.
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