The XC3S5000-4FG676I is a high-capacity, cost-optimized Field Programmable Gate Array (FPGA) from Xilinx’s Spartan-3 family. Designed for industrial-grade applications requiring extended temperature tolerance and robust programmable logic, this device delivers 5 million system gates in a compact 676-pin Fine-pitch Ball Grid Array (FBGA) package. Whether you are developing telecom infrastructure, industrial automation, or embedded processing systems, the XC3S5000-4FG676I offers the performance and flexibility engineers rely on.

If you are evaluating programmable logic solutions, explore our full range of Xilinx FPGA products to find the right fit for your design.

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What Is the XC3S5000-4FG676I?

The XC3S5000-4FG676I is a member of Xilinx’s Spartan-3 FPGA family — an eight-member lineup spanning 50,000 to 5,000,000 system gates. The “XC3S5000” designates the 5-million-gate device, “4” indicates the -4 speed grade, “FG676” refers to the 676-ball FBGA package, and “I” signifies the industrial temperature range (–40°C to +100°C junction temperature). This part number combination makes it the industrial-grade variant of the largest Spartan-3 device in the FG676 package.

Built on 90nm process technology and powered at 1.2V core supply, the XC3S5000-4FG676I strikes an outstanding balance between gate density, memory resources, clock management capability, and I/O flexibility — all at a price point suited for high-volume production environments.

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XC3S5000-4FG676I Key Specifications at a Glance

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XC3S5000-4FG676I Detailed Features

## Logic Resources and Configurable Logic Blocks (CLBs)

The XC3S5000-4FG676I contains 8,320 Configurable Logic Blocks arranged in a regular array. Each CLB holds four slices, and each slice includes two 4-input Look-Up Tables (LUTs) and two storage elements usable as flip-flops or latches. The LUTs double as 16-bit distributed shift registers, providing flexible logic implementation for complex state machines, data path logic, and DSP-style processing.

Key logic capabilities include:

• 74,880 equivalent logic cells
• Fast look-ahead carry logic for efficient arithmetic operations
• Wide multiplexer support (F6MUX, F7MUX, F8MUX) for large function implementations
• LUT-based shift registers (SRL16) for pipelining and delay chains
• JTAG boundary scan compatible with IEEE 1149.1 and IEEE 1532 standards

## Block RAM and SelectRAM Memory Architecture

The XC3S5000-4FG676I features a hierarchical memory architecture that supports both block RAM and distributed RAM, giving designers flexible data storage choices within the FPGA fabric.

Each of the four block RAM columns runs the full height of the device. The dual-port structure allows simultaneous, independent access from two separate data ports, supporting high-bandwidth data buffering, FIFOs, and embedded memory interfaces.

## Dedicated 18×18-Bit Multipliers

The XC3S5000-4FG676I integrates 104 dedicated 18×18-bit hardware multipliers, each co-located next to a block RAM. These multipliers accept two 18-bit multiplicands and deliver a 36-bit product on the output bus. The synchronous MULT18X18S variant includes registered outputs, enabling high-speed pipelined DSP operations such as:

• Digital filters (FIR, IIR)
• Fast Fourier Transforms (FFT)
• Matrix multiplication for signal and image processing
• Spread-spectrum modulation/demodulation

Because the multipliers share interconnects with block RAM but operate simultaneously, designers can achieve high MAC (multiply-accumulate) throughput without consuming CLB logic resources.

## Digital Clock Manager (DCM)

The XC3S5000-4FG676I includes four Digital Clock Managers providing advanced clock control features critical for timing closure in complex designs.

The four DCMs on this device enable multi-clock domain designs with precise relationships between each domain, which is essential in applications such as Ethernet interfaces, DDR memory controllers, and synchronous communication protocols.

## SelectIO: I/O Standards and Pin Capabilities

The 676-ball FCBGA package exposes up to 448 user I/O pins, supporting 26 distinct signal standards — 18 single-ended and 8 differential. The Digitally Controlled Impedance (DCI) feature provides automatic on-chip termination, eliminating the need for external resistors on high-speed signal lines.

DDR operation uses a pair of IOB flip-flops combined with a special multiplexer (FDDR primitive), clocked on both rising and falling clock edges, typically with DCM-generated complementary clocks.

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XC3S5000-4FG676I Ordering and Part Number Decoder

Understanding the part number helps engineers select the correct variant for their design:

The “I” temperature suffix is critical for applications in harsh or uncontrolled environments. The commercial “C” variant (XC3S5000-4FG676C) is rated only from 0°C to +85°C and is not suitable for industrial deployment.

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XC3S5000-4FG676I vs. Other Spartan-3 Variants

If higher I/O count is required, the FG900 or FG1156 packages provide up to 633 I/O pins. Note that the FG1156 package has been discontinued and is not recommended for new designs.

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XC3S5000-4FG676I Configuration and Programming

Spartan-3 FPGAs are configured by loading bitstream data into internal static CMOS configuration latches (CCLs). The XC3S5000-4FG676I supports five configuration modes:

1. Master Serial – Single PROM-based serial configuration
2. Slave Serial – Controlled by an external processor or CPLD
3. Master Parallel (SelectMAP) – Fast byte-wide parallel configuration
4. Slave Parallel (SelectMAP) – Byte-wide parallel mode driven externally
5. JTAG – IEEE 1149.1/1532 boundary scan and in-system programming

Configuration data is stored externally in a serial PROM (such as the Xilinx Platform Flash XCF series) or in a system processor’s NOR/NAND flash memory. The FPGA reconfigures on every power cycle unless a configuration source is permanently connected.

Design tools for the XC3S5000-4FG676I include Xilinx ISE Design Suite (legacy) and the Vivado Design Suite (recommended for continued support and advanced optimization).

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XC3S5000-4FG676I Application Areas

Thanks to its high gate density, abundant block RAM, dedicated DSP multipliers, and industrial temperature rating, the XC3S5000-4FG676I is deployed across a broad range of industries:

### Telecommunications and Networking

• Line cards, switches, and routers requiring flexible protocol processing
• Gigabit Ethernet PHY interfaces and packet buffering using block RAM FIFOs
• Broadband access equipment including DSL modems and optical network units

### Industrial Automation and Control

• Programmable Logic Controller (PLC) expansion modules
• Motor drive control with multi-axis PWM generation
• Real-time sensor data acquisition with DDR memory interfaces

### Aerospace and Defense

• Radar signal processing with hardware-accelerated FFT using dedicated multipliers
• Secure communication equipment requiring custom encryption hardware
• Avionics data bus controllers (MIL-STD-1553, ARINC 429) leveraging FPGA reconfigurability

### Medical Devices

• Ultrasound imaging signal processing
• Patient monitoring systems requiring reliable operation across temperature extremes
• High-speed data acquisition front-ends

### Consumer and Embedded Systems

• Display processing and video scaler pipelines
• Home networking gateways with custom MAC layer logic
• Digital television and set-top box signal processing

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XC3S5000-4FG676I Package and Thermal Information

Thermal management is particularly important for the XC3S5000-4FG676I when operating at full utilization in industrial environments. Xilinx recommends using the XPower Estimator tool to calculate actual power dissipation based on toggle rates, clock frequency, and resource utilization before finalizing the board design.

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XC3S5000-4FG676I Frequently Asked Questions (FAQ)

Q: What is the difference between XC3S5000-4FG676I and XC3S5000-4FGG676I? The “FGG” variant includes the Pb-free (“G”) designation in the package code, indicating a RoHS-compliant, lead-free solder ball composition. The “FG” variant uses standard leaded solder. Electrically, both parts are functionally identical.

Q: Is the XC3S5000-4FG676I still recommended for new designs? The Spartan-3 family is a mature product. For new designs, Xilinx (now AMD) recommends evaluating the Spartan-6 family (e.g., XC6SLX150) or the Artix-7 series for improved performance and lower power. The XC3S5000-4FG676I remains fully available for legacy system maintenance and production continuity.

Q: What development software supports the XC3S5000-4FG676I? Xilinx ISE Design Suite is the primary legacy toolchain. Vivado provides limited support for Spartan-3; ISE 14.7 is the recommended version for full Spartan-3 synthesis, implementation, and bitstream generation.

Q: Can the XC3S5000-4FG676I be used in automotive applications? The standard XC3S5000-4FG676I is rated for industrial temperatures. For automotive-qualified parts, Xilinx offers the XA (Automotive) Spartan-3 family variants, which undergo AEC-Q100 qualification testing.

Q: What are suitable replacement/alternative parts for the XC3S5000-4FG676I? Pin-compatible alternatives within the Spartan-3 family include the XC3S4000-4FG676I (4M gates) and XC3S2000-4FG676I (2M gates). Functional upgrades include the Xilinx Spartan-6 XC6SLX150-2FGG676I, which offers significantly higher performance in a compatible BGA footprint.

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Summary: Why Choose the XC3S5000-4FG676I?

The XC3S5000-4FG676I remains a proven, production-ready FPGA for engineers who need maximum gate density within the Spartan-3 FG676 footprint, combined with industrial-grade reliability. Its combination of 5 million system gates, 1,728 Kbits of block RAM, 104 dedicated multipliers, four DCMs, and 448 user I/O pins — all operating across a –40°C to +100°C temperature range — continues to satisfy demanding applications in telecom, industrial, aerospace, and medical markets.

For a complete selection of programmable logic devices, explore our Xilinx FPGA product catalog.