Managing Unused Gtx Transceivers; Analog Power Supply Pins - Xilinx Virtex-6 FPGA User Manual

Chapter 5: Board Design Guidelines

Managing Unused GTX Transceivers

In many applications, only a portion of the GTX transceivers are required. There are
considerations for managing the unused GTX transceivers that affect such things as power
consumption of the Virtex-6 FPGA. When considering which Quads to use in an
application, the organization of the package power planes needs to be taken into account.
Power can be utilized efficiently when there are multiple analog power planes in the
package. If only a small number of the Quads are to be used, it might be possible to leave
some of them completely unpowered.
The criteria for powering a GTX QUAD is based on whether the GTX transceivers will be
permanently unused or whether they will be used at a later date. If a GTX transceiver is
ever intended to be used, it must be powered whenever the FPGA is powered up. If the
GTX transceiver will never be used, the transceiver bank can be unpowered. Connections
to unused GTX transceivers (including power supplies) are covered in the following
sections.

Analog Power Supply Pins

The Quad analog power supply pins, MGTAVCC and MGTAVTT, have planes inside the
package. Some packages have two planes for each of these analog power supplies,
designated as north and south. Therefore, the Quads in a column are grouped by their
common analog power supply connections into banks. There are north and south banks of
Quads. For each of the analog power supplies, pins for all of the north Quads are
connected to the same plane inside the package. Similarly, for each of the analog power
supplies, the pins for the south bank of Quads are connected to the same plane inside the
package. As a result, there are four Quad analog power supply planes inside the package.
Inside the package are two MGTAVCC power planes and two MGTAVTT power planes.
Refer to
In
•
•
Table 5-2: Connected Quads
Device
MGT110
(2)
XC6VLX75T-FF484
(2)
XC6VLX75T-FF784
(2)
XC6VLX130T-FF484
(2)
XC6VLX130T-FF784
XC6VLX130T-FF1156
(2)
XC6VLX195T-FF784
XC6VLX195T-FF1156
(2)
XC6VLX240T-FF784
XC6VLX240T-FF1156
XC6VLX240T-FF1759
XC6VLX365T-FF1156
XC6VLX365T-FF1759
XC6VLX550T-FF1759 South
XC6VSX315T-FF1759
www.BDTIC.com/XILINX
276
Table 5-2 for a description of the connected Quads.
Table 5-2, there are two types of groupings of the Quads in a column.
Devices with two banks of Quads in a column:
• North bank of Quads
• South bank of Quads
Devices with one bank of Quads in a column
MGT111 MGT112
(4,6)
South
South
South
South
South
South
South South
South
www.xilinx.com
(1)
Quad
MGT113 MGT114 MGT115
(3)
Common Common
Common Common
Common Common
Common Common
South South North
Common Common
South South North
Common Common
South South North
South South North
South South North
South South North
South South North
South South North
Virtex-6 FPGA GTX Transceivers User Guide
MGT116 MGT117
Common
Common
(5,6)
North
Common
North
Common
North
North North
North
North North
North North
North North
UG366 (v2.5) January 17, 2011
MGT118
North