Using the Transceiver Sheets (GTP, GTX, GTH, GTY, GTZ) - 2020.2 English

Xilinx Power Estimator User Guide (UG440)

Document ID
UG440
Release Date
2020-12-04
Version
2020.2 English

Different Xilinx device families have Multi-Gigabit Transceivers (MGT), which are very high performance serial I/Os. Transceivers typically use separate voltage supplies for the PCS, PMA and termination.

To understand the capabilities of the 7 series GTs and the settings within XPE refer to the 7 Series FPGAs GTX/GTH Transceivers User Guide (UG476) and the 7 Series FPGAs GTP Transceivers User Guide (UG482).

To understand the capabilities of the UltraScale device GTs and the settings within XPE refer to the UltraScale Architecture GTH Transceivers User Guide (UG576) and the UltraScale Architecture GTY Transceivers User Guide (UG578).
Important: In the 7 series/Zynq-7000 SoC XPE spreadsheets, PCI Express (PCIe) information is specified on a GTX, GTP, GTH, or GTZ sheet. In the UltraScale and UltraScale+ XPE spreadsheets, all of the Hard IP Blocks (PCIe - GEN1, GEN2 & GEN3) and 100G Ethernet (CMAC & ILKN) are specified on the GTH or GTY sheets. Spreadsheets for earlier Xilinx devices have a separate PCIe sheet.

To simplify data entry, drop-down menus are provided with parameter preferred or required values. The following figure shows an example Kintex-7 XC7K325T design. The tables in the sheet header report design power and currents. Device leakage for each supply is reported on the Summary sheet.

For 7 series devices, XPE provides a Transceiver Interface Configuration wizard to allow you to quickly enter the important parameters required for an accurate transceiver power estimate. For step-by-step instructions about how to use the wizard to fill out the MGT sheets, see Using the Transceiver Configuration Wizard.

XPE calculates power for each channel including the power of all associated circuits, shared resources between channels, I/O buffers, reference clock circuitry, and so forth. You therefore do not have to enter resource usage on any other sheet (for example, Clock or I/O) to describe the transceiver resources used.

XPE presents the MGT information in an architecture-specific way. Entering 2 or any multiple of 2 channels for a GTP/GTX_DUAL entry assumes that those channels use the minimum number of DUALs. Similarly, for GTHE1 and GTXE2 4 channels share common circuitry, so XPE assumes each line uses the minimum number of quads. To use 2 channels from one quad and 2 from another, specify them on two rows in XPE.

Tip: For Spartan-6 devices, you can specify a GTPA1_DUAL with different settings for each channel by entering each channel on a separate row using the same base name suffixed with _0 and _1 (for example, GTP_0 and GTP_1). A red border around the cells of two adjacent rows indicates the two GTPA1s are inferred to be in the same GTPA1_DUAL.

The Power Planes field in the MGT sheet represents the number of power planes used in the design. MGT transceivers require multiple analog power supplies for the PMA (Physical Medium Attachment). The number of power planes varies by device and package. When not all available MGTs are used, it might be possible to ground unused power planes to reduce the static power.

In the UltraScale and 7 series/Zynq-7000 SoC XPE spreadsheets, the GTX, GTP, GTH, and GTY sheets have an OOB Used column. The OOB feature uses out-of band (OOB) signaling for PCIe and other protocols where the physical connection may be unplugged during operation. OOB is supported using high-speed amplitude detection on the inputs and squelch on the corresponding outputs. A Yes in the OOB Used column indicates that your design will use this feature.

Tip: For a description of the Eye Scan feature, which you can set to On or Off in the GTX, GTH, and GTY MGT sheets, see the 7 Series FPGAs GTX/GTH Transceivers User Guide (UG476), the UltraScale Architecture GTH Transceivers User Guide (UG576), or the UltraScale Architecture GTY Transceivers User Guide (UG578).
Tip: In the 7 series GTX sheet, you can set the Power Mode for GTX transceivers to Low Power or DFE. For a description of the low-power mode (LPM) and the decision feedback equalization (DFE) mode, see the RX Equalizer (DFE and LPM) section in the 7 Series FPGAs GTX/GTH Transceivers User Guide (UG476).

XPE does not support all of the possible MGT configurations. See the specific Transceiver User Guide for more information.

Figure 1. GT Power Sheet (Kintex-7 Devices) Illustrating Data Rate and Power Estimates