Software Developer’s Manual 303
Register Descriptions
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.
Field Bit(s)
Initial
Value
Description