Stratix V FPGA Transceivers

Altera® transceivers have a proven track record of meeting system bandwidth, power, and bit-error rate (BER) requirements. The technology leadership continues with the transceivers in our 28 nm Stratix® V FPGAs.

Building on their predecessors, Stratix V FPGA transceivers come with many enhancements for flexibility and robustness:

  • Additional low-jitter LC transmit phase-locked loops (PLLs)
  • Robust analog receive clock data recovery (CDR)
  • Advanced equalization for 10GBASE-KR backplane support
  • Integration of on-die instrumentation
  • Best-in-class transceiver data rates at 14.1 Gbps and 28.05 Gbps

Backplane Applications

Video: Driving Backplanes with High-Speed FPGA Transceivers

Stratix V GX/GS FPGAs are designed for backplane applications. Altera’s Stratix V GX/GS transceivers offer a number of programmable and adaptive equalization features designed to handle the challenges of backplane links including:

  • 4-tap transmit pre-emphasis
  • Continuous time-linear equalizers (CTLE)
  • Adaptive decision feedback equalizers (DFE)

These solutions are designed to provide the most amount of flexibility and performance at the lowest power in an FPGA transceiver to address the range of problems that are encountered in backplane applications, including 10GBASE-KR backplanes. For more information, please read our whitepaper on Backplane Applications with 28 nm FPGAs (PDF) as well as our application notes on designing high-speed PCBs for backplane applications.


Stratix V FPGAs feature up to 66 full-duplex transceiver channels, with transceivers at data rates from 14.1 Gbps to 28.05 Gbps. Providing up to over 930 Gbps of transceiver bandwidth, Stratix V FPGAs deliver the highest system bandwidth at the lowest power consumption for a wide range of applications and protocols. In addition, the transceivers are compliant with a range of protocols and are equipped with a variety of signal conditioning features to support backplane, optical module, and chip-to-chip applications. See our best-in-class transceiver eye diagrams at 14.1 Gbps and 28 Gbps shown in Figure 1 and Figure 2.

Figure 1. Stratix V GS/GX 14.1 Gbps Eye Diagram

Click to see full size

Figure 2. Stratix V GT 28 Gbps Eye Diagram

Click to see full size

Stratix V transceivers also include full-featured embedded physical coding sublayer (PCS) hard intellectual property (IP) to simplify design, lower power, and save valuable core resources. The Stratix V FPGA transceiver channel consists of the physical media attachment (PMA), PCS, and hardened IP blocks with added clocking flexibility and more independent channels. Each channel has a full PMA and PCS along with a dedicated, independent receive analog PLL CDR. You'll have access to an abundant number of transmit clocking sources, including the wide data range support of the clock multiplication unit (CMU) as well as the low-jitter LC transmit PLLs. Plus, you can minimize the number of off-chip crystal oscillators by utilizing the new fractional PLLs (fPLLs) with precise frequency synthesis. Not only can the fPLLs generate fractional multiples of a reference clock, they can also be used to drive the transceiver reference clock. Figure 3 shows some of the key architectural features for Stratix V FPGA transceivers.

Figure 3. Stratix V Transceiver Channel Components

Transceiver PMA

The flexible PMA is designed to be compliant across a wide range of protocols and mediums. Advanced equalization, on-die instrumentation, and partial reconfiguration are just some of the many PMA features offered on Stratix V FPGA transceivers. See Table 1 for more information on PMA features and capabilities.

Table 1. Transceiver PMA Features

Features Capability
Backplane, chip-to-chip, and chip-to-module support at up to 14.1 GbpsStratix V GX and GS FPGAs
Chip-to-chip and chip-to-module support at up to 28.05 GbpsStratix V GT FPGAs
Optical module support with electronic dispersion compensation (EDC)XFP, SFP+, QSFP, CXP, CFP
Cable driving supportPCI Express® (PCIe®) cable and eSATA applications
Adaptive continuous-time linear equalization (AEQ)4-stage linear equalization to support high-attenuation channels with high gain and low power
Adaptive DFEAdaptive 5-tap digital equalizer to minimize losses and crosstalk
Analog PLL-based clock recoverySuperior jitter tolerance compared to phase-interpolation-based clock recovery
Programmable deserialization and word alignmentFlexible deserialization width and configurable word-alignment patterns
Transmit equalization (pre-emphasis)Transmit driver with 4-tap FIR pre-emphasis and de-emphasis for protocol compliance under lossy conditions
Ring and LC oscillator transmit PLLsChoice of transmit PLLs per channel, optimized for lowest power and wide tuning range
On-die instrumentation (EyeQ data-eye monitor)Allows non-intrusive on-chip monitoring of both width and height of data eye
Dynamic and partial reconfigurationAllows reconfiguration of single channels and the core on the fly, while other portions of the design are still running
Protocol supportCompliance with over 50 industry-standard protocols

Transceiver PCS and Hard Protocol Support

The Stratix V FPGA core logic connects to the PCS via an 8, 10, 16, 20, 32, 40, 64, or 66 bit interface, depending on the transceiver data rate and protocol. Stratix V FPGAs contain hard IP blocks to support PCIe Gen3, Gen2, and Gen1, as well as hardened PCS features to support 40G/100G Ethernet, Interlaken, 10 Gbps Ethernet (10GbE), Serial RapidIO®, and CPRI. Figure 4 details some of the main building blocks in the PCS to support the broad range of protocols.

Figure 4. PCS Building Blocks





Stay Informed