DS537 Datasheet, PDF (125/148 Pages) Xilinx, Inc – LogiCORE IP XPS LL TEMAC

LogiCORE IP XPS LL TEMAC (v2.03a)
The Physical Medium Attachment (PMA) for 1000BASE-X operation is defined in IEEE 802.3 clause 36 and
performs the following:
• Serialization (and de serialization) of code-groups for transmission (and reception) on the underlying serial
PMD
• recovery of clock from the 8B/10B coded data supplied by the PMD
1000BASE-X PCS/PMA functionality is provided by connecting the Hard TEMAC silicon component to a RocketIO
transceiver.
PMD
The Physical Medium Dependent (PMD) sublayer is defined in IEEE 802.3 clause 38 for 1000BASE-LX and
1000BASE-SX (long and short wave laser). This type of PMD is provided by the external GBIC or SFP optical
transceiver which should be connected directly to the ports of the RocketIO transceiver.
Virtex 4 Hard TEMAC 1000BASE-X Constraints
Refer to Answer Record 32713 for constraint examples. Refer to UG625 for an overview of the various constraints
used.
1000BASE-X Auto-Negotiation
1000BASE-X auto negotiation is described in IEEE Std 802.3, clause 37. This function allows a device to advertise the
supported modes of operation to a device at the remote end of a link segment (the link partner on Ethernet), and
detect corresponding operational modes advertised by the link partner.
The results of the auto negotiation can be read from the 1000BASE-X Management Auto negotiation Link Partner
Ability Base Register (Table 118). The duplex mode and speed of the XPS_LL_TEMAC should then be set to match
(see "TEMAC Receive Configuration Word 1 (RCW1) Registers" on page 51, "TEMAC Transmit Configuration (TC)
Registers" on page 52, and "TEMAC Ethernet MAC Mode Configuration (EMMC) Registers" on page 54).
There are two methods that may be used to learn of the completion of an auto negotiation cycle:
• By polling the auto negotiation complete bit of 1000BASE-X Management Status Register (Register 1, bit 5
Table 114).
By using the auto negotiation complete interrupt (see "Interrupt Status Registers (IS0 and IS1)" on page 29 and
1000BASE-X Management Auto Negotiation Interrupt Control Register Table 123 on page 131.)
Loopback
There are two possible loopback positions:
• Loopback in the Hard TEMAC silicon component. When placed into loopback, data is routed from the
transmitter to the receiver path at the last possible point in the PCS/PMA sublayer. This is immediately before
the RocketIO transceiver interface. When placed into loopback, a constant stream of Idle code groups is
transmitted through the RocketIO transceiver. Loopback in this position allows test frames to be looped back
within the system without allowing them to be received by the link partner (the device connected on the other
end of the Ethernet. The transmission of Idles allows the link partner to remain in synchronization so that no
fault is reported.
• Loopback in the RocketIO transceiver. The RocketIO transceiver can be switched into loopback and will route
data from the transmitter path to the receiver path within the RocketIO transceiver. However, this data is also
transmitted out of the RocketIO transceiver and so any test frames used for a loopback test will be received by
the link partner.
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