Overview of XC18V512VQG44C FPGA Configuration Memory
The XC18V512VQG44C is a 512-kilobit in-system programmable configuration PROM designed specifically for configuring Xilinx FPGA devices. This industrial-grade configuration memory offers exceptional reliability and flexibility for embedded systems requiring field-programmable configurations. With lead-free packaging and advanced CMOS FLASH technology, the XC18V512VQG44C delivers robust performance across demanding industrial applications.
Key Features and Specifications
Core Technical Specifications
| Specification |
Value |
| Memory Capacity |
512 Kilobits (524,288 bits) |
| Package Type |
44-pin VQFP (VQG44) Lead-Free |
| Supply Voltage (VCCINT) |
3.0V to 3.6V |
| Output Voltage (VCCO) |
2.5V or 3.3V Compatible |
| Operating Temperature |
-40°C to +85°C (Industrial) |
| Program/Erase Cycles |
20,000 Cycles |
| Data Retention |
20 Years Minimum |
| Configuration Clock |
Up to 33 MHz |
Advanced Configuration Capabilities
The XC18V512VQG44C supports dual configuration modes for maximum versatility:
- Serial Configuration Mode: Slow/Fast serial configuration up to 33 MHz
- Parallel Configuration Mode: High-speed parallel transfer up to 264 Mb/s at 33 MHz
Pin Configuration and Package Details
VQG44 Package Pin Information
| Pin Function |
Pin Count |
Description |
| Data Output (D0-D7) |
8 pins |
Parallel/Serial data output |
| Control Pins |
4 pins |
CLK, CE, OE/RESET, CEO |
| JTAG Interface |
4 pins |
TCK, TMS, TDI, TDO |
| Power Supply |
Multiple |
VCCINT, VCCO, GND |
| Configuration Pin |
1 pin |
CF (Configuration initiation) |
The 44-pin VQFP package provides comprehensive pin access while maintaining a compact footprint suitable for space-constrained PCB designs.
XC18V512VQG44C Configuration Modes
Master Serial Mode Operation
In Master Serial mode, the XC18V512VQG44C works seamlessly with FPGA devices operating in Master Serial configuration. The FPGA generates the configuration clock (CCLK) which drives the PROM, enabling autonomous configuration without external timing sources.
Master Serial Mode Features:
- FPGA-driven clock generation
- Simple interface with minimal external components
- Single data line (D0) for serial bitstream delivery
- Automatic configuration initiation on power-up
Slave Serial and Parallel Modes
For applications requiring external clock control or higher bandwidth, the XC18V512VQG44C supports slave configuration modes where an external oscillator or master device controls timing.
Compatible Xilinx FPGA Devices
| FPGA Series |
Compatible Devices |
Configuration Solution |
| Spartan-II |
XC2S15, XC2S30 |
Single XC18V512 |
| Spartan-IIE |
XC2S50E |
Single XC18V512 |
| Spartan-3 |
XC3S50 |
Single XC18V512 |
| Virtex-II |
XC2V40 |
Single XC18V512 |
The XC18V512VQG44C provides sufficient memory capacity for small to medium-sized FPGA configurations, making it ideal for cost-sensitive applications.
In-System Programming Features
JTAG Programming Interface
The XC18V512VQG44C incorporates full IEEE 1149.1 Boundary-Scan (JTAG) compliance, enabling:
- In-system programming without device removal
- Field upgrades for deployed systems
- Chain programming of multiple devices
- Design iteration flexibility
Programming Specifications
| Parameter |
Specification |
| Programming Interface |
IEEE 1149.1 JTAG |
| Endurance |
20,000 Program/Erase Cycles |
| Data Security |
Programmable Read Protection |
| IDCODE |
05023093h or revision variants |
Electrical Characteristics and Performance
DC Operating Parameters
The XC18V512VQG44C maintains robust electrical performance across industrial temperature ranges:
| Parameter |
Condition |
Min |
Max |
Unit |
| Supply Current (Active) |
25 MHz operation |
– |
25 |
mA |
| Supply Current (Standby) |
CE High |
– |
10 |
mA |
| High-Level Output |
IOH = -4mA |
2.4 |
– |
V |
| Low-Level Output |
IOL = 8mA |
– |
0.4 |
V |
| Input Leakage |
VCCINT = Max |
-10 |
+10 |
μA |
AC Timing Characteristics
XC18V512 Fast Timing Parameters:
| Timing Parameter |
Description |
Min |
Max |
| TCYC |
Clock Period |
30 ns |
– |
| TCAC |
Clock to Data Delay |
– |
15 ns |
| TOE |
OE to Data Delay |
– |
10 ns |
| TCE |
CE to Data Delay |
– |
15 ns |
| TOCK |
Clock to CEO Delay |
– |
20 ns |
Power Management and Reliability
Power-On Reset Functionality
The XC18V512VQG44C includes robust power-on reset circuitry ensuring reliable configuration initiation:
- Automatic reset when VCCINT rises above threshold
- Configurable delay for power supply stabilization
- OE/RESET pin for system-level coordination
Environmental and Reliability Standards
| Reliability Factor |
Specification |
| ESD Protection |
2000V minimum |
| Data Retention |
20 years at 85°C |
| Temperature Cycling |
-40°C to +85°C |
| Moisture Sensitivity |
Lead-free compliant |
Cascading and Multi-Device Configuration
The XC18V512VQG44C supports cascading for larger configuration requirements:
Cascade Configuration Benefits
- Expandable memory by chaining multiple PROMs
- CEO output enables seamless device transition
- Shared clock and data lines simplify routing
- Compatible with XC18V00 and XC17V00 families
Design Security Features
Configuration Protection
The XC18V512VQG44C provides advanced security options:
- Read protection prevents unauthorized bitstream access
- JTAG security bit blocks configuration readback
- Erase-only access when security enabled
- Design IP protection for proprietary configurations
Application Examples
Typical Use Cases
- Industrial Automation: FPGA configuration in PLC and control systems
- Communications Equipment: Reconfigurable networking hardware
- Medical Devices: Field-upgradeable diagnostic equipment
- Aerospace Systems: Reliable configuration storage for avionics
Design Considerations and Best Practices
PCB Layout Recommendations
- Place bypass capacitors (0.1μF) close to VCCINT pins
- Use pull-up resistors (4.7kΩ) on DONE and OE/RESET
- Minimize trace lengths between PROM and FPGA
- Implement proper grounding for signal integrity
Configuration Timing Optimization
| Design Factor |
Recommendation |
| Clock Frequency |
Use maximum supported frequency for faster configuration |
| Pull-up Values |
Follow FPGA datasheet specifications |
| Signal Routing |
Keep configuration signals away from high-speed data |
| Power Sequencing |
Ensure VCCINT rises monotonically within 50ms |
Ordering Information and Package Marking
Part Number Breakdown
XC18V512VQG44C = XC18V (family) + 512 (kilobits) + VQG44 (44-pin VQFP lead-free) + C (industrial temp)
Package Identification
The XC18V512VQG44C package markings include:
- Device family and density
- Package type indicator
- Temperature grade
- Manufacturing date code
Comparison with Other Configuration PROMs
| Model |
Capacity |
Package Options |
Max Speed |
| XC18V512VQG44C |
512 Kb |
44-pin VQFP, 20-pin SOIC/PLCC |
33 MHz |
| XC18V01 |
1 Mb |
Same options |
33 MHz |
| XC18V02 |
2 Mb |
Same options |
33 MHz |
| XC18V04 |
4 Mb |
Same options |
33 MHz |
Quality and Compliance Standards
The XC18V512VQG44C meets stringent quality requirements:
- RoHS Compliant lead-free construction
- Industrial temperature grade qualification
- JEDEC standards compliance
- Xilinx quality assurance testing
Technical Support and Resources
Development Tools
Configure the XC18V512VQG44C using:
- Xilinx iMPACT programming software
- ISE Design Suite integration
- Third-party programmers supporting JTAG
- SVF file generation for automated test equipment
Conclusion
The XC18V512VQG44C represents a reliable, cost-effective solution for FPGA configuration storage. With its robust 512-kilobit capacity, industrial-grade specifications, and comprehensive programming features, this configuration PROM addresses the needs of modern embedded systems requiring field-programmable flexibility. The lead-free VQG44 package combines environmental compliance with excellent thermal and electrical performance, making the XC18V512VQG44C an ideal choice for next-generation FPGA-based designs.
Whether you’re developing industrial controls, communication systems, or aerospace applications, the XC18V512VQG44C provides the configuration memory reliability and performance your project demands.
