IP-10GETHERNET Altera, IP-10GETHERNET Datasheet - Page 41

• Manufacturer Part Number: IP-10GETHERNET
• Description: IP CORE - 10 Gbps Ethernet MAC PCS PMA Reference Design
• Manufacturer: Altera

Specifications of IP-10GETHERNET

• Software Application: IP CORE, Interface And Protocols, ETHERNET
• Supported Families: Quartus II
• Core Architecture: FPGA
• Core Sub-architecture: Stratix
• Rohs Compliant: NA
• Lead Free Status / RoHS Status: na

MAC Functional Description
Figure 3–14. Flow of Frame through the MAC Rx
Notes to
(1) <p> = payload size = 0–1500 bytes.
(2) <s> = pad bytes = 0–46 bytes.
© July 2010 Altera Corporation
MAC Frame
Start[7:0]
Figure
3–14:
Preamble
[47:0]
The following section describe the functions performed by the Rx MAC.
3.2.4.1. Preamble Processing
The preamble sequence is Start, six preamble bytes, and SFD. If this sequence is
incorrect the frame is ignored. The start word must be on receive lane 0 (most
significant byte). The IP core uses the SFD byte (0xD5) to identify the last byte of the
preamble. The MAC Rx looks for the Start, six preamble bytes and SFD. The MAC Rx
removes all Start, SFD and IFG bytes from accepted frames. To be accepted the
preamble must be preceded by a column of Idle ||I|| or an ordered set (for example,
a local fault).
3.2.4.2. Payload Padding Removal
If the incoming frame includes padding, it is removed before forwarding the frame to
Rx client. Padding removal may be optional depending on the payload length and the
value of the PAD_EN bit in the command_config register. The IP core removes the
padding, prior to sending the frames to the Rx FIFO, when the PAD_EN bit is set to 1
and the payload length is less than the following values for the different frame types:
■
■
■
If the PAD_EN bit is set to 0, complete frames including the padding are forwarded to
the client.
3.2.4.3. CRC Checking
The 32-bit CRC field is received in the order: X
MSB of FCS field and occupies the LSB position on first FCS byte field. If a CRC-32
error is detected, the MAC Rx marks the frame invalid by asserting the
avl_st_rx_err.
3.2.4.4. Rx CRC Forwarding
The CRC-32 field is forwarded to the client interface if the CRC_FWD bit of the
command_config register is set.
46 bytes for basic frames
42 bytes for VLAN tagged frames
38 bytes for stacked VLAN tagged frames
SFD[7:0]
Client Frame
Destination
Destination
Addr[47:0]
Addr[47:0]
Client - MAC Rx Interface
Addr[47:0]
Addr[47:0]
Source
Source
Length[15:0]
Type/
32
, X
30
PAD [<s>-1:0]
, . . . X
10-Gbps Ethernet IP Functional Description
(optional)
1
, and X
CRC32
[31:0]
0
, where X
EFD[7:0]
32
is the
3–15