Xilinx 1000BASE-X - Manual (Page 24)

24 www.xilinx.com Ethernet 1000BASE-X PCS/PMA or SGMII v9.1
UG155 March 24, 2008
Chapter 2: Core Architecture R
GMII Block
A client-side GMII is provided with the core, which can be used as an internal interface for
connection to an embedded Media Access Controller (MAC) or other custom logic.
Alternatively, the GMII may be routed to device IOBs to provide an external (off chip)
GMII.
PCS Transmit Engine
The PCS transmit engine converts the GMII data octets into a sequence of ordered sets by
implementing the state diagrams of IEEE 802.3 (figures 36-5 and 36-6). See
Appendix D,
“1000BASE-X State Machines.”
PCS Receive Engine and Synchronization
The synchronization process implements the state diagram of IEEE 802.3 (figure 36-9). The
PCS receive engine converts the sequence of ordered sets to GMII data octets by
implementing the state diagrams of IEEE 802.3 (figures 36-7a and 36-7b). See
Appendix D,
“1000BASE-X State Machines.”
Optional Auto-Negotiation Block
IEEE 802.3 clause 37 describes the 1000BASE-X Auto-Negotiation function that allows a
device to advertise the modes of operation that it supports to a device at the remote end of
a link segment (link partner), and to detect corresponding operational modes that the link
partner may be advertising.
Auto-Negotiation is controlled and monitored through the PCS Management Registers.
See
Chapter 10, “Auto-Negotiation.”
Figure 2-1: Functional Block Diagram Using RocketIO Transceiver
PCS Transmit Engine
PCS Receive Engine
and Synchronization
Roc
k
e
tIO
T
ranseiv
er
Optional PCS
Management
GMII
to MAC
MDIO
Interface
Optional
Auto-Negotiation
To PMD
Sublayer
GMII Bloc
k
LogiCORE Ethernet 1000BASE-X PCS/PMA or SGMII Core
Roc
k
e
tIO I/F Bloc
k