Understanding Xilinx part numbers is crucial for engineers, designers, and procurement professionals working with Field-Programmable Gate Arrays (FPGAs) and System-on-Chip (SoC) devices. Xilinx, now part of AMD, has developed a systematic naming convention that encodes essential information about each device’s capabilities, package type, performance grade, and other critical specifications. This comprehensive guide will help you decode these part numbers and make informed decisions when selecting devices for your projects.
Overview of Xilinx Naming Convention
Xilinx part numbers follow a structured format that contains multiple segments, each representing specific device characteristics. The general format typically includes device family, size/capacity, speed grade, package type, and temperature grade. Understanding this structure allows you to quickly identify whether a particular device meets your project requirements without needing to reference detailed datasheets for basic specifications.
The naming convention has evolved over the years as Xilinx has introduced new device families and technologies. While older families like Spartan-3 and Virtex-4 follow slightly different patterns, the core principles remain consistent across all product lines. Modern devices, including the Zynq UltraScale+ and Versal families, use more sophisticated naming schemes that reflect their advanced capabilities.
Device Family Identification
The first part of any Xilinx part number identifies the device family. This is perhaps the most important element as it determines the overall architecture, technology node, and available features. Common family prefixes include:
XC7 series represents the 7-series devices, including Artix-7, Kintex-7, and Virtex-7 families. These devices are built on 28nm technology and offer excellent performance-per-watt ratios. The Artix-7 family focuses on low power and cost optimization, while Kintex-7 provides balanced performance and power consumption. Virtex-7 devices offer the highest performance and capacity within the 7-series lineup.
XCZU designates Zynq UltraScale+ devices, which combine ARM processors with FPGA fabric on advanced FinFET technology nodes. These heterogeneous devices are designed for applications requiring both software programmability and hardware acceleration. The integrated ARM Cortex-A53 and Cortex-R5 processors make them ideal for embedded systems requiring real-time processing capabilities.
XCKU and XCVU represent Kintex UltraScale+ and Virtex UltraScale+ families, respectively. These devices focus purely on FPGA functionality without integrated processors, offering maximum logic density and performance for compute-intensive applications.
XCK and XCV indicate older UltraScale devices (without the plus designation), which preceded the UltraScale+ generation. While still capable devices, they lack some of the advanced features found in newer families.
Size and Capacity Indicators
Following the family identifier, Xilinx part numbers include size indicators that represent the device’s logic capacity and available resources. These numbers don’t directly correspond to gate counts but rather indicate relative sizes within each family.
For 7-series devices, numbers like 15, 25, 35, 50, 75, 100, and 200 indicate increasing logic capacity. An XC7A35T has fewer logic cells than an XC7A100T, which in turn has fewer than an XC7A200T. The “T” suffix indicates that the device includes transceivers for high-speed serial communication.
UltraScale+ devices use different numbering schemes. For example, XCZU7EV indicates a mid-range Zynq UltraScale+ device with video codec capabilities (EV suffix), while XCZU19EG represents a larger device with enhanced graphics processing capabilities.
The capacity numbers help engineers select devices with appropriate resources for their applications. Choosing a device that’s too small may result in design constraints or inability to implement required functionality, while oversized devices increase costs unnecessarily.
Speed Grade Specifications
Speed grades indicate the maximum performance characteristics of a device, typically expressed as negative numbers where lower (more negative) values represent faster devices. Common speed grades include -1, -2, and -3, with -3 being the fastest grade available for most families.
The speed grade affects several critical timing parameters, including maximum clock frequencies, setup and hold times, and routing delays. Faster speed grades come at premium prices and often consume more power, so selecting the appropriate grade requires balancing performance requirements with cost and power constraints.
When interpreting speed grades, remember that the actual achievable performance depends heavily on your specific design implementation, synthesis settings, and routing complexity. A -1 speed grade device might be sufficient for designs with modest timing requirements, while high-performance applications may require -2 or -3 grades to meet timing closure.
Package Type Identification
Package information appears toward the end of Xilinx part numbers and indicates the physical form factor and pin configuration. Common package types include:
BGA (Ball Grid Array) packages are the most common for modern Xilinx devices. Numbers following BGA indicate the pin count and sometimes the package dimensions. For example, FBGA676 represents a fine-pitch BGA with 676 balls, while FBGA900 has 900 balls. The package size affects the number of available I/O pins and the device’s thermal characteristics.
CSG (Chip Scale Grid) packages offer smaller form factors with reduced pin counts, suitable for space-constrained applications. These packages typically sacrifice some I/O capability for reduced board space requirements.
RF (Flip Chip) packages provide excellent thermal performance and are often used in high-power applications. The flip-chip construction offers superior heat dissipation compared to wire-bonded alternatives.
QFP (Quad Flat Pack) packages, while less common in modern devices, may still be found in some older families or specialized applications. These packages use leads extending from all four sides and are easier to inspect visually than BGA packages.
Temperature Grade Classifications
Temperature grades specify the operating temperature range for reliable device operation. Xilinx uses letter suffixes to indicate temperature grades:
C (Commercial) grade devices operate from 0°C to +85°C and are suitable for most indoor applications, office environments, and consumer electronics. These devices offer the best cost-performance ratio for applications without extreme environmental requirements.
I (Industrial) grade devices function from -40°C to +100°C, making them suitable for industrial automation, automotive applications, and outdoor installations. The extended temperature range comes with slightly higher costs but provides reliability in challenging environments.
M (Military) grade devices operate from -55°C to +125°C and meet stringent military specifications for reliability and performance. These devices command premium prices but offer the highest reliability for critical applications.
Advanced Feature Indicators
Modern Xilinx devices include various advanced features indicated by specific suffixes or designators within the part number:
EV (Evaluation Video) suffix in Zynq UltraScale+ devices indicates integrated video codec capabilities, including H.264 and H.265 encoding/decoding hardware. These devices are optimized for video processing applications.
EG (Evaluation Graphics) designation indicates enhanced graphics processing capabilities, often including Mali GPU cores for 3D graphics acceleration.
DR (Data Rate) specifications may appear in transceivers-heavy devices, indicating the maximum supported data rates for high-speed serial interfaces.
RF (Radio Frequency) designations in some devices indicate specialized RF processing capabilities, including direct RF sampling and digital up/down conversion features.
Ordering Code Structure
Complete Xilinx ordering codes include additional information beyond the basic part number. A typical ordering code might look like: XC7A100T-2FGG484C
Breaking this down:
- XC7A100T: Artix-7, size 100, with transceivers
- 2: Speed grade -2
- FGG484: Fine-pitch BGA, 484 balls
- C: Commercial temperature grade
Some ordering codes include additional suffixes indicating packaging options, lead-free compliance (most modern devices), or special screening requirements.
Special Considerations and Variants
Xilinx occasionally releases special variants of standard devices with unique characteristics. These might include automotive-qualified versions with AEC-Q100 certification, radiation-hardened devices for aerospace applications, or devices with enhanced security features.
Engineering samples and pre-production devices may have different part number formats or additional suffixes indicating their developmental status. These should not be used in production designs without careful consideration of their limitations and availability.
Practical Application and Selection Guidelines
When selecting Xilinx devices, start by identifying the required device family based on your application needs. Consider factors like processing requirements, power consumption, I/O requirements, and special features. Use the capacity indicators to ensure adequate logic resources while avoiding unnecessary oversizing.
Speed grade selection should be based on your timing requirements with appropriate margins for design iterations and process variations. Package selection depends on board space constraints, I/O requirements, and thermal management needs.
Temperature grade selection should account for the operating environment with appropriate derating for altitude, airflow, and power dissipation. Industrial or military grades may be necessary even if the nominal temperature range seems adequate.
Conclusion
Understanding Xilinx part numbers enables efficient device selection and reduces the risk of choosing inappropriate devices for your applications. The systematic naming convention encodes critical information that helps engineers make informed decisions quickly. As Xilinx continues to evolve under AMD ownership, the basic principles of their naming convention remain consistent, making this knowledge valuable for both current and future device generations.
Mastering part number interpretation is an essential skill for anyone working with Xilinx devices, whether for initial design selection, procurement, or design migration between device variants. This knowledge foundation will serve you well as you navigate the extensive Xilinx product portfolio and make optimal device selections for your projects.
