Sun Microsystems GigaSwift Ethernet Adapter Network Card User Manual


 
44 Sun GigaSwift Ethernet Adapter Installation and Users Guide August 2004
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
fewer 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
fewer 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
fewer 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 Determines the multiplication factor for granting credit to the TX
side during a weighted round robin arbitration. Values are 0 to 3.
(Default=0) 0 means no extra weighting. The other values are power
of 2 extra weighting, on that traffic. For example if 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