Intel PCI User Manual

299

PMCF

23

0b

Pass MAC Control Frames
0b = Do not (specially) pass MAC control frames.
1b = Pass any MAC control frame (type field value of 8808h) that 
does not contain the pause opcode of 0001h.
PMCF controls the DMA function of MAC control frames (other than 
flow control). A MAC control frame in this context must be 
addressed to either the MAC control frame multicast address or the 
station address, match the type field and NOT match the PAUSE 
opcode of 0001h. If PMCF = 1b then frames meeting this criteria are 
transferred to host memory. Otherwise, they are filtered out.

Reserved

24

0b

Reserved
Should be written with 0b to ensure future compatibility.
Reads as 0b.

BSEX

25

0b

Buffer Size Extension
When set to one, the original BSIZE values are multiplied by 16. 
Refer to the RCTL.BSIZE bit description.

SECRC

26

0b

Strip Ethernet CRC from incoming packet
0b = Do not strip CRC field.
1b = Strip CRC field.
Controls whether the hardware strips the Ethernet CRC from the 
received packet. This stripping occurs prior to any checksum 
calculations. The stripped CRC is not transferred to host memory 
and is not included in the length reported in the descriptor.

Reserved

31:27

0b

Reserved
Should be written with 0b to ensure future compatibility.
Reads as 0b.

1.

Not applicable to the 82541ER.