Altera Cyclone IV Device Handbook page 339

Chapter 1: Cyclone IV Transceivers Architecture
Transceiver Functional Modes
1
Cyclone IV GX transceivers do not have built-in support for some PCS functions such
as auto-negotiation state machine, collision-detect, and carrier-sense. If required, you
must implement these functions in a user logic or external circuits.
The 1000 Base-X PHY is defined by IEEE 802.3 standard as an intermediate or
transition layer that interfaces various physical media with the media access control
(MAC) in a GbE system. The 1000 Base-X PHY, which has a physical interface data
rate of 1.25 Gbps consists of the PCS, PMA, and physical media dependent (PMD)
layers.
Figure 1–54. 1000 Base-X PHY in a GbE OSI Reference Model
Notes to
(1) CSMA/CD = Carrier-Sense Multiple Access with Collision Detection
(2) GMII = gigabit medium independent interface
February 2015 Altera Corporation
Figure 1–54 shows the 1000 Base-X PHY in LAN layers.
LAN CSMA/DC Layers
Logical Link Control (LLC) or other MAC client
MAC Control (Optional)
Reconcilation
Figure 1–54:
(1)
Higher Layers
MAC
GMII
(2)
PCS
PMA 1000 Base-X PHY
PMD
Medium
1–59
Cyclone IV Device Handbook,
Volume 2