Product Overview: AMD/Xilinx XCS40XL-4BG256I FPGA
The XCS40XL-4BG256I is a powerful Field Programmable Gate Array (FPGA) from AMD’s (formerly Xilinx) renowned Spartan-XL family, engineered to deliver exceptional performance for high-volume production applications. This industrial-grade FPGA combines cost-effectiveness with robust functionality, making it an ideal ASIC replacement solution for designers seeking flexibility without compromising on reliability or performance.
As part of the Xilinx FPGA ecosystem, the XCS40XL-4BG256I represents a proven solution for embedded system designers requiring programmable logic capabilities with industrial temperature tolerance.
Key Technical Specifications
Core Performance Features
| Specification |
Value |
| Logic Gates |
40,000 gates |
| Logic Cells |
1,862 cells |
| Configurable Logic Blocks (CLBs) |
784 CLBs |
| Maximum System Clock |
217 MHz |
| Internal Performance |
>150 MHz |
| Supply Voltage |
3.3V (3.0V – 3.6V range) |
Memory and I/O Capabilities
| Feature |
Specification |
| Total RAM Bits |
25,088 bits |
| On-Chip RAM |
Dual-port block RAM |
| Maximum User I/O |
205 pins |
| Package Type |
256-pin BGA (Ball Grid Array) |
| Pin Pitch |
1.27mm |
Environmental and Reliability Specifications
| Parameter |
Range/Value |
| Operating Temperature |
-40°C to +100°C (Industrial grade) |
| Temperature Grade |
“I” – Industrial |
| Speed Grade |
-4 (high performance) |
| Package Height |
Maximum 2.55mm |
| Technology Node |
Advanced CMOS process |
Product Architecture and Design
Advanced FPGA Architecture
The XCS40XL-4BG256I leverages the proven XC4000 architecture foundation with significant enhancements derived from XC4000XLA process developments. This sophisticated design provides:
- Symmetrical and regular architecture optimized for placement and routing algorithms
- VersaRing routing architecture surrounding the CLB array for maximum interconnect flexibility
- Programmable Switch Matrix (PSM) enabling flexible signal routing
- Multiple routing resources including single-length lines, double-length lines, and longlines
Configurable Logic Blocks (CLBs)
Each CLB in the XCS40XL-4BG256I features:
- Distributed on all four sides for maximum routing flexibility
- Internal carry logic for efficient arithmetic operations
- Flexible function generators that can swap positions to avoid routing congestion
- High-speed internal connections for optimal performance
On-Chip Memory Resources
The integrated 25,088-bit RAM provides:
- Dual-port block RAM capability
- Flexible memory configurations
- High-speed access for data-intensive applications
- Reduced need for external memory components
Application Areas and Use Cases
Industrial Automation and Control
The XCS40XL-4BG256I excels in demanding industrial environments:
- Process control systems
- Motor control applications
- Industrial protocols implementation (Fieldbus, CAN, Profibus)
- PLC replacement and enhancement
- Real-time monitoring systems
Communications Equipment
Ideal for telecommunications infrastructure:
- Protocol conversion and bridging
- Data packet processing
- Signal conditioning and filtering
- Interface controllers
- Wireless infrastructure components
Enterprise Systems
Perfect for business-critical applications:
- Data acquisition systems
- Enterprise machine control
- Embedded computing platforms
- Server management controllers
- Network interface cards
Consumer Electronics
Suitable for portable and personal electronics:
- Portable medical devices
- Consumer IoT devices
- Audio/video processing
- Display controllers
- Battery-powered applications (low power mode support)
Key Features and Benefits
Cost-Effective ASIC Replacement
The XCS40XL-4BG256I provides a compelling alternative to traditional ASICs:
- Eliminates NRE costs associated with mask-programmed ASICs
- Reduces development time from months to weeks
- Provides design flexibility for late-stage modifications
- Minimizes financial risk for low to medium volume production
- Enables rapid prototyping and iterative design
Advanced Configuration Options
Multiple configuration modes support diverse system requirements:
- Master Serial Mode: FPGA generates its own clock for configuration
- Slave Serial Mode: External controller manages configuration
- Boundary-Scan (JTAG): IEEE 1149.1/1532 compliant for programming and testing
- In-System Programming: Update designs without removing the device
Industrial-Grade Reliability
Built for harsh environments:
- Extended temperature range (-40°C to +100°C)
- Industrial-grade screening and testing
- Proven reliability in mission-critical applications
- Robust ESD protection
Power Management Features
Optimized for power-sensitive applications:
- Power-Down Mode: Significantly reduces current consumption
- PWRDWN pin control with internal pull-up resistor
- Selective power gating of unused resources
- Efficient 3.3V operation reducing overall system power
Design Tools and Development Support
Compatible Development Software
The XCS40XL-4BG256I is supported by industry-standard FPGA design tools:
- Xilinx ISE Design Suite: Legacy but comprehensive development environment
- Third-party synthesis tools: Synplify, Precision RTL, and others
- FPGA Editor: Visual design review and manual routing
- Impact Programming Tool: Device configuration and programming
Hardware Development Resources
Engineers can accelerate development with:
- Reference designs and application notes
- Evaluation boards (compatible with Spartan-XL family)
- Development kits for rapid prototyping
- Technical documentation and datasheets
- Community forums and technical support
Package Information: 256-Pin BGA
Package Advantages
The BG256 package provides optimal characteristics for modern PCB design:
- Compact footprint: 17mm x 17mm body size
- Fine pitch: 1.27mm ball spacing
- Excellent thermal performance: Low thermal resistance
- High I/O density: 205 user I/Os in small package
- Standard PCB compatibility: Compatible with FR-4 substrates
PCB Design Considerations
For successful implementation:
- Via-in-pad technology recommended for routing
- Minimum 6-layer PCB for complex designs
- Proper power plane decoupling critical
- Thermal vias beneath package for heat dissipation
- Controlled impedance routing for high-speed signals
Quality and Compliance
Regulatory Status
- RoHS Compliance: Not RoHS compliant (contains lead)
- REACH: Not compliant with REACH regulations
- Export Classification: ECCN Code EAR99
- Lifecycle Status: Obsolete (replacement parts available)
Quality Standards
Manufactured to stringent quality requirements:
- Automotive-grade processes for industrial applications
- 100% functional testing
- Comprehensive reliability testing
- ISO-certified manufacturing facilities
Technical Support and Documentation
Available Resources
Comprehensive technical documentation includes:
- Complete datasheet with electrical specifications
- Application notes for common implementations
- PCB layout guidelines
- Thermal management recommendations
- Configuration bitstream format documentation
CAD Resources
Design engineers can access:
- IBIS models for signal integrity analysis
- BSDL files for boundary-scan testing
- 3D STEP models for mechanical design
- PCB footprints for major CAD systems
- Symbol libraries for schematic capture
Ordering Information and Availability
Part Number Breakdown
XCS40XL-4BG256I nomenclature explained:
- XCS: Spartan-XL family designation
- 40: 40,000 system gates
- XL: Extended features version
- -4: Speed grade (higher number = faster performance)
- BG256: 256-pin Ball Grid Array package
- I: Industrial temperature range (-40°C to +100°C)
Alternative Part Numbers
Consider these related devices:
- XCS40XL-3BG256I: Lower speed grade for cost optimization
- XCS40XL-4BG256C: Commercial temperature range version
- XCS40XL-4PQ208I: 208-pin PQFP package alternative
- XCS40XL-4CS280I: 280-pin CSBGA for maximum I/O
Replacement and Upgrade Path
Obsolescence Notice
While the XCS40XL-4BG256I is classified as obsolete, AMD (Xilinx) offers modern alternatives:
- Spartan-6 LX series: Pin-compatible upgrades with enhanced features
- Spartan-7 family: Latest generation with improved performance and lower power
- Artix-7 series: High-performance migration path
Migration Considerations
When upgrading from XCS40XL:
- Review pin compatibility and I/O standards
- Update development tools to latest versions
- Verify power supply requirements
- Test timing closure with new devices
- Validate configuration procedures
Competitive Advantages
Why Choose XCS40XL-4BG256I
The Spartan-XL series continues to offer value:
- Proven track record: Millions of units deployed worldwide
- Long-term support: Extensive documentation and community knowledge
- Cost-effective: Competitive pricing for legacy designs
- Design reuse: Existing designs require minimal modification
- Supply chain: Multiple distribution channels available
Comparison with Alternatives
| Feature |
XCS40XL-4BG256I |
Typical CPLD |
ASIC |
| Gate Count |
40,000 |
<10,000 |
Custom |
| Flexibility |
High |
Medium |
None |
| NRE Cost |
$0 |
$0 |
High |
| Unit Cost |
Medium |
Low |
Very Low* |
| Time to Market |
Days |
Days |
Months |
| Design Changes |
Easy |
Easy |
Impossible |
*ASIC cost advantage only at very high volumes
Frequently Asked Questions
What is the maximum clock frequency?
The XCS40XL-4BG256I supports system clock rates exceeding 217 MHz with internal logic running above 150 MHz, depending on design complexity and routing.
Can this FPGA operate at 5V?
No, the XCS40XL-4BG256I operates at 3.3V nominal (3.0V-3.6V range). However, I/O pins can be configured for 5V tolerance when required for interfacing with legacy systems.
What configuration file size is required?
The bitstream size for the XCS40XL-4BG256I is approximately 227 Kbits, depending on configuration options selected.
Is in-system programming supported?
Yes, the device supports in-system programming through JTAG (IEEE 1149.1/1532) interface, enabling field updates without removing the component.
What is the typical power consumption?
Power consumption varies with design utilization and clock frequency. Static power is typically below 100mA, while dynamic power depends on switching activity.
Conclusion
The XCS40XL-4BG256I remains a reliable choice for industrial FPGA applications requiring proven performance, industrial temperature tolerance, and cost-effective implementation. While classified as obsolete, its extensive documentation, robust architecture, and established supply chain make it suitable for legacy design support and applications where design stability is paramount.
For new designs, consider modern Spartan-7 or Artix-7 alternatives that offer enhanced performance, lower power consumption, and long-term availability. However, for existing designs and applications requiring drop-in replacements, the XCS40XL-4BG256I continues to deliver the reliability and performance that has made the Spartan-XL family a cornerstone of industrial FPGA applications.
