Sun Microsystems 806-2989-10 Network Card User Manual


 
32 Sun GigaSwift Ethernet Adapter Installation and User’s Guide February 2001
PCI Bus Interface Parameters
These parameters allow you to modify PCI interface features to gain better PCI
interperformance for a given application.
red_dv6to8k 0 to 255 Random early detection and packet drop vectors for
when fifo threshold is greater than 6,144 bytes and less
than 8,192 bytes. Probability of drop can be
programmed on a 12.5 percent granularity. For
example, if bit 8 is set the first packet out of every eight
will be dropped in this region. (Default=0)
red_dv8to10k 0 to 255 Random early detection and packet drop vectors for
when fifo threshold is greater than 8,192 bytes and less
than 10,240 bytes. Probability of drop can be
programmed on a 12.5 percent granularity. For
example, if bit 16 is set the first packet out of every
eight will be dropped in this region. (Default=0)
red_dv10to12k 0 to 255 Random early detection and packet drop vectors for
when fifo threshold is greater than 10,240 bytes and less
than 12,288 bytes. Probability of drop can be
programmed on a 12.5 percent granularity. For
example, if bit 24 is set the first packet out of every
eight will be dropped in this region. (Default=0)
TABLE 4-9 PCI Bus Interface Parameters
Parameter Description
tx_dma_weight Determine the multiplication factor for granting credit to the TX
side during a weighted round robin arbitration. Values are 0 to 3.
(Default=0) Zero
means no extra weighting. The other values
are power of 2 extra weighting, on that traffic. For example
of tx_dma_weight = 0 and rx_dma_weight = 3 then as long
as RX traffic is continuously arriving its priority will be 8
times greater than TX to access the PCI
TABLE 4-8 RX Random Early Detecting 8-Bit Vectors
Field Name Values Description