Data Sheet
Ethernet Controller I210 — Programming Interface
436
8.10.2 Split and Replication Receive Control - SRRCTL (0xC00C +
0x40*n [n=0...3]; R/W)
Reserved 25:24 0x0
Reserved.
Write 0x0, ignore on read.
SECRC 26 0b
Strip Ethernet CRC From Incoming Packet
Causes the CRC to be stripped from all packets.
0b = Does not strip CRC.
1b = Strips CRC.
This bit 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.
Notes:
1. If the CTRL.VME bit is set the RCTL.SECRC bit should also be set as the CRC is
not valid anymore.
2. Even when this bit is set, CRC strip is not done on runt packets (smaller than 64
bytes).
Reserved 31:27 0x0
Reserved.
Write 0x0, ignore on read.
Field Bit(s) Initial Value Description
BSIZEPACKET 6:0 0x0
Receive Buffer Size for Packet Buffer.
The value is in 1 KB resolution. Valid values can be from 1 KB to 16 KB. Default
buffer size is 0 KB. If this field is equal 0x0, then RCTL.BSIZE determines the packet
buffer size.
DMACQ_Dis 7 0b
DMA Coalescing Disable.
0b= Enable DMA coalescing on this queue if DMACR.DMAC_EN is set to 1b.
1b = Disable DMA coalescing on this queue. When a packet is destined to this queue
and the device is in coalescing mode, coalescing mode is exited immediately and
PCIe moves to the L0 link power management state.
BSIZEHEADER 13:8 0x4
Receive Buffer Size for Header Buffer.
The value is in 64 bytes resolution. Valid value can be from 64 bytes to 2048 bytes
(BSIZEHEADER = 0x1 to 0x20). Default buffer size is 256 bytes. This field must be
greater than 0 if the value of DESCTYPE is greater or equal to 2.
Note: When SRRCTL.Timestamp is set to 1b and the value of SRRCTL.DESCTYPE is
greater or equal to 2, BSIZEHEADER size should be equal or greater than 2
(128 bytes).
Reserved 19:14 0x0
Reserved.
Write 0x0, ignore on read.
RDMTS 24:20 0x0
Receive Descriptor Minimum Threshold Size.
A Low Latency Interrupt (LLI) associated with this queue is asserted each time the
number of free descriptors becomes equal to RDMTS multiplied by 16.
DESCTYPE 27:25 000b
Defines the descriptor in Rx.
000b = Legacy.
001b = Advanced descriptor one buffer.
010b = Advanced descriptor header splitting.
011b = Advanced descriptor header replication - replicate always.
100b = Advanced descriptor header replication large packet only (larger than header
buffer size).
Reserved.
111b = Reserved.
Field Bit(s) Initial Value Description