The XC3S400-5FGG456C is a high-performance, cost-optimized Field-Programmable Gate Array (FPGA) from the Xilinx Spartan-3 family. Manufactured using advanced 90nm process technology, this device delivers 400K system gates, 8,064 logic cells, and operates at up to 725 MHz — making it an ideal solution for high-volume, consumer-grade, and embedded applications. Whether you are designing communication systems, industrial controllers, or digital signal processing platforms, the XC3S400-5FGG456C offers unmatched flexibility and programmability at a competitive price point.
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What Is the XC3S400-5FGG456C?
The XC3S400-5FGG456C is part of Xilinx’s eight-member Spartan-3 FPGA family, a product line specifically engineered for cost-sensitive, high-volume electronic applications. The device combines abundant logic resources, high-speed I/O capabilities, embedded block RAM, and digital clock management into a compact 456-ball Fine-Pitch Ball Grid Array (FBGA) package.
This FPGA is designed as a superior, reprogrammable alternative to mask-programmed ASICs. Unlike ASICs, it eliminates high non-recurring engineering (NRE) costs and allows in-field design updates without hardware replacement — a critical advantage for products that require post-deployment upgrades or iterative development cycles.
XC3S400-5FGG456C Key Specifications
General Specifications
| Parameter |
Value |
| Manufacturer |
AMD / Xilinx |
| Part Number |
XC3S400-5FGG456C |
| Product Family |
Spartan-3 |
| Series |
XC3S400 |
| Operating Temperature |
0°C to +85°C (Commercial Grade) |
| Core Supply Voltage |
1.2V |
| Process Technology |
90nm CMOS |
| Package Type |
456-Ball FBGA (Fine-Pitch Ball Grid Array) |
| Package Marking |
FGG456 (Lead-Free, “G” designator) |
| RoHS Compliance |
Yes |
Logic & Performance Specifications
| Parameter |
Value |
| System Gates |
400,000 |
| Logic Cells |
8,064 |
| CLB (Configurable Logic Blocks) |
1,152 |
| CLB Flip-Flops |
8,064 |
| Maximum Frequency |
725 MHz |
| 4-Input LUTs |
8,064 |
| Distributed RAM |
231 Kbits |
| Block RAM |
288 Kbits (16 × 18K blocks) |
| Dedicated Multipliers (18×18-bit) |
16 |
| Digital Clock Managers (DCMs) |
4 |
I/O & Connectivity Specifications
| Parameter |
Value |
| Total Package Pins |
456 |
| User I/O Pins |
264 |
| Maximum Data Rate per I/O |
622+ Mb/s |
| Supported Single-Ended Standards |
18 |
| Supported Differential Standards |
8 (including LVDS, RSDS) |
| DDR / DDR2 SDRAM Support |
Up to 333 Mb/s |
| JTAG Support |
IEEE 1149.1 / IEEE 1532 |
| Signal Swing Range |
1.14V – 3.465V |
| Global Clock Lines |
8 |
| DCI (Digitally Controlled Impedance) |
Yes |
| Double Data Rate (DDR) Support |
Yes |
XC3S400-5FGG456C Part Number Decoder
Understanding the part number helps engineers quickly identify key device characteristics:
| Code Segment |
Meaning |
| XC3S |
Xilinx Spartan-3 Family |
| 400 |
400K System Gate Count |
| 5 |
Speed Grade (5 = Fastest in series) |
| FGG |
Fine-Pitch Ball Grid Array, Lead-Free (G = Pb-free) |
| 456 |
456 Package Pins |
| C |
Commercial Temperature Range (0°C to +85°C) |
XC3S400-5FGG456C Architecture Overview
Configurable Logic Blocks (CLBs)
The XC3S400-5FGG456C features 1,152 CLBs arranged in a regular, tile-based array. Each CLB contains four slices, and every slice includes two 4-input Look-Up Tables (LUTs), two storage elements (flip-flops), wide multiplexers, and fast carry logic. The LUTs can also function as distributed 16-bit shift registers or 16-bit synchronous RAM, adding versatility to the fabric.
Block RAM (SelectRAM™)
The device provides 288 Kbits of on-chip Block RAM organized as 16 true dual-port 18Kbit blocks. Each block supports independent read and write port widths, making the memory subsystem highly flexible for FIFO buffers, data queues, lookup tables, and on-chip storage in embedded processor designs.
Dedicated 18×18 Multipliers
Sixteen dedicated 18×18-bit two’s complement multipliers are embedded within the device. Each multiplier is co-located with a block RAM to support high-throughput DSP pipelines, including MAC (Multiply-Accumulate) operations for filtering, FFT computation, and digital communications.
Digital Clock Manager (DCM)
Four on-chip Digital Clock Managers (DCMs) provide clock skew elimination, frequency synthesis, and high-resolution phase shifting. The DCM supports both DLL (Delay-Locked Loop) and DCM (Digital Clock Manager) modes, enabling zero-skew distribution of clocks across the full device fabric.
SelectIO™ Interface Technology
The XC3S400-5FGG456C supports 18 single-ended and 8 differential I/O standards via Xilinx’s SelectIO™ technology, including LVDS, RSDS, LVPECL, SSTL, HSTL, and more. Digitally Controlled Impedance (DCI) enables on-chip termination, eliminating the need for external resistors and simplifying PCB layout in high-speed applications.
Applications for the XC3S400-5FGG456C
The XC3S400-5FGG456C is well suited for a wide range of embedded and system-level designs:
| Application Domain |
Use Cases |
| Communications |
Packet processing, protocol bridging, serializers/deserializers |
| Industrial Automation |
Motor control, PLC acceleration, sensor interfacing |
| Consumer Electronics |
Display controllers, set-top boxes, digital audio/video processing |
| Medical Devices |
Signal acquisition, imaging front-ends, patient monitoring |
| Embedded Computing |
MicroBlaze soft-core processor, custom co-processors |
| Test & Measurement |
Protocol analyzers, signal generators, data capture systems |
| Defense & Aerospace |
FPGA-based prototyping (industrial-grade variants recommended) |
XC3S400-5FGG456C vs. Other Spartan-3 Variants
| Part Number |
Gates |
Logic Cells |
I/O Pins |
Package |
Temp Grade |
| XC3S200-5FGG320C |
200K |
4,320 |
173 |
FGG320 |
Commercial |
| XC3S400-5FGG456C |
400K |
8,064 |
264 |
FGG456 |
Commercial |
| XC3S1000-5FGG456C |
1M |
17,280 |
391 |
FGG456 |
Commercial |
| XC3S1500-5FGG456C |
1.5M |
29,952 |
487 |
FGG456 |
Commercial |
| XC3S400-4FGG456I |
400K |
8,064 |
264 |
FGG456 |
Industrial (–40°C to +100°C) |
Note: If your design requires operation in harsh environments, consider the XC3S400-4FGG456I (industrial temperature grade) variant.
Development Tools & Programming
Supported Design Software
The XC3S400-5FGG456C is fully supported by:
- Xilinx ISE Design Suite – The primary design environment for Spartan-3 devices, offering synthesis, implementation, simulation, and device programming flows.
- Vivado Design Suite – While primarily targeted at 7-Series and newer devices, Vivado can be used for certain IP-based flows.
- MicroBlaze Soft-Core Processor – Embed a 32-bit RISC processor within the FPGA fabric for embedded software execution.
- ModelSim / Questa – Industry-standard HDL simulators for pre-synthesis and post-implementation simulation.
Configuration Modes
The device supports five configuration modes:
| Mode |
Description |
| Master Serial |
Uses external SPI or Serial Flash PROM |
| Slave Serial |
Controlled by external master device |
| Master Parallel (SelectMAP) |
Byte-wide parallel configuration |
| Slave Parallel (SelectMAP) |
Parallel configuration under external control |
| JTAG |
Boundary-scan compliant IEEE 1149.1/1532 |
Ordering Information
| Parameter |
Detail |
| Manufacturer Part Number |
XC3S400-5FGG456C |
| Manufacturer |
AMD (formerly Xilinx) |
| DigiKey Part Number |
122-1474-ND |
| Package |
456-FBGA |
| Minimum Order Quantity |
1 (tray) |
| RoHS Status |
RoHS Compliant |
| Moisture Sensitivity Level |
MSL 3 |
XC3S400-5FGG456C Frequently Asked Questions
Q: What is the core voltage of the XC3S400-5FGG456C?
A: The device operates at a core supply voltage of 1.2V, while I/O voltages vary by standard (1.14V–3.465V range).
Q: Is the XC3S400-5FGG456C lead-free?
A: Yes. The “G” in the package designator (FGG456) confirms that this is a Pb-free, RoHS-compliant package.
Q: What is the maximum operating temperature?
A: The “C” suffix indicates a commercial temperature grade, supporting 0°C to +85°C ambient operation.
Q: Can I replace an XC3S400-5FGG456C with an industrial variant?
A: The XC3S400-4FGG456I is the industrial-temperature equivalent, operating from –40°C to +100°C. Note the speed grade is 4 instead of 5 in the industrial variant.
Q: What programming tools are required?
A: Xilinx ISE Design Suite (version 14.x recommended) with a compatible JTAG programmer such as Xilinx Platform Cable USB II or third-party equivalents.
Q: How many user I/Os are available in the 456-ball package?
A: The FGG456 package provides 264 user-selectable I/O pins.
Summary
The XC3S400-5FGG456C is a mature, well-supported FPGA that continues to serve demanding embedded design projects requiring a proven, cost-effective programmable logic platform. With 400K gates, 8,064 logic cells, 725 MHz operation, and 264 user I/Os in a compact 456-ball FBGA package, it provides substantial compute density for consumer, industrial, and communication applications. Its compatibility with Xilinx ISE tooling, broad I/O standard support, and reprogrammable architecture make it a practical alternative to fixed-function ASICs.
Engineers sourcing the XC3S400-5FGG456C should verify RoHS compliance, moisture sensitivity handling (MSL 3), and confirm toolchain compatibility prior to design commitment.
