Altera 40-Gbps Ethernet MAC and PHY MegaCore Function User Manual
Page 167
Term
Definition
FCS
Frame Check Sequence. A CRC-32 with bit reordering and inversion.
Frame
Ethernet formatted packet. A frame consists of a start delimiter byte, a 7 byte
preamble, variable length data, 4-byte FCS, and an end delimiter byte.
IPG
Inter Packet Gap. Includes the end of frame delimiter and subsequent IDLE
bytes up to, but not including the next start of frame delimiter. The protocol
requires an average gap of 12 bytes.
MAC
Media Access Control. Formats a user packet stream into proper Ethernet
frames for delivery to the PCS. The MAC generates the FCS and checks and
maintains the IPG.
MII
Media Independent Interface. The byte-oriented protocol used by the PCS.
Sometimes distinguished with roman numerals, XGMII (10), XLGMII (40),
CGMII (100).
Octet
Byte. Note that Ethernet specifications primarily use least significant bit first
ordering which is opposite from the default behavior of most contemporary
CAD tools.
PCS
Physical Coding Sublayer. Presents the underlying hardware as a byte-oriented
communication channel.
XLAUI
40 gigabit attachment unit interface. (XL is the symbol in Roman Numerals for
40). This is an electrical interface that which is based on a 4-lane interface with a
bandwidth of 10 Gbps per lane.
XLGMII
40 gigabit media independent interface. (XL is the symbol in Roman Numerals
for 40). This is the byte-oriented interface protocol that connects the PCS and
MAC.
3-120
Ethernet Glossary
UG-01088
2014.12.15
Altera Corporation
Functional Description