Overview of XC18V04-VQ44C Configuration Memory
The XC18V04-VQ44C is a high-performance, in-system programmable configuration PROM (Programmable Read-Only Memory) manufactured by AMD (formerly Xilinx). This 4-megabit configuration memory device operates at 3.3V and comes in a compact 44-pin VQFP package, making it an ideal solution for storing FPGA configuration bitstreams. As part of the XC18V00 series, this configuration PROM provides engineers with a cost-effective and reliable method for programming and storing Xilinx FPGA configuration data.
Key Technical Specifications
Electrical Characteristics
| Parameter |
Specification |
| Memory Capacity |
4 Megabits (4Mb) |
| Memory Organization |
512K x 8 bits |
| Supply Voltage |
3.0V to 3.6V |
| Operating Temperature |
0°C to +70°C (Commercial grade) |
| Access Time |
20ns |
| Programming Type |
In-System Programmable (ISP) |
Package Information
| Feature |
Details |
| Package Type |
44-VQFP (Very Thin Quad Flat Pack) |
| Package Dimensions |
10mm x 10mm |
| Pin Count |
44 pins |
| Mounting Type |
Surface Mount Device (SMD) |
| Thermal Resistance |
~50°C/W (θJA) |
Product Features and Benefits
In-System Programmability
The XC18V04-VQ44C offers exceptional flexibility through its in-system programming capability. This feature enables engineers to update configuration data without removing the device from the circuit board, significantly reducing maintenance time and costs in production environments.
Non-Volatile Memory Storage
Unlike volatile memory solutions, this configuration PROM retains data without power, ensuring your FPGA configurations remain intact through power cycles and system shutdowns. This reliability is crucial for mission-critical applications where data integrity is paramount.
Cascading Capability
Multiple devices can be cascaded using the CEO output to drive the CE input of the following device, with all clock inputs and DATA outputs interconnected. This architecture allows for larger configuration storage by combining multiple PROMs in a daisy-chain configuration.
IEEE 1149.1 JTAG Boundary-Scan
The device supports standard JTAG boundary-scan testing, facilitating easier board-level testing and debugging. This feature is essential for quality assurance in manufacturing processes.
Pin Configuration and Interface
Primary Pin Functions
| Pin Function |
Description |
| VCC |
Power supply pins (3.3V nominal) |
| GND |
Ground reference pins |
| D0-D7 |
8-bit parallel configuration data output |
| CE# |
Chip Enable (active low) |
| OE# |
Output Enable (active low) |
| WE# |
Write Enable for programming |
| CEO |
Chip Enable Output for cascading |
| CLK |
Configuration clock input |
Compatibility and Applications
FPGA Configuration Support
The XC18V04-VQ44C is specifically designed to work seamlessly with Xilinx FPGA families. When the FPGA operates in Master Serial mode, it generates the configuration clock that drives the PROM, automatically loading the stored bitstream during power-up or reconfiguration.
Target Applications
Telecommunications Systems
Configuration PROMs like the XC18V04-VQ44C are essential in telecommunications infrastructure where FPGAs handle signal processing, protocol conversion, and data routing. The reliable non-volatile storage ensures network equipment boots correctly every time.
Industrial Automation
In industrial control systems, this device stores critical FPGA configurations that control manufacturing processes, robotics, and monitoring systems. The wide operating temperature range makes it suitable for harsh industrial environments.
Consumer Electronics
From high-definition video processing to advanced audio systems, the XC18V04-VQ44C provides the configuration storage needed for consumer devices requiring flexible, field-upgradable logic.
Automotive Technology
Modern vehicles increasingly rely on FPGA-based systems for advanced driver assistance, infotainment, and engine control. This configuration memory ensures reliable operation across automotive temperature ranges.
Programming and Configuration
In-System Programming Process
The XC18V04-VQ44C can be programmed through standard JTAG interfaces using industry-standard programming tools. This capability eliminates the need for dedicated programming hardware in production, reducing manufacturing complexity and cost.
Configuration Data Storage
The device stores up to 4 megabits of configuration data, sufficient for medium to large FPGA designs. The 20ns access time ensures rapid configuration loading, minimizing system boot times.
User-Programmable Features
The device includes a 32-bit user-programmable scratch pad for device identification, allowing engineers to store version information, serial numbers, or other identifying data alongside the configuration bitstream.
Compliance and Quality Standards
Environmental Compliance
| Standard |
Status |
| RoHS Compliance |
Meets RoHS requirements |
| MSL Rating |
Moisture Sensitivity Level per JEDEC standards |
| ESD Protection |
Packaged according to ESD protection requirements |
Quality Assurance
The XC18V04-VQ44C undergoes rigorous testing to ensure reliability in demanding applications. Quality control measures include electrical parameter testing, temperature cycling, and long-term reliability validation.
Design Considerations
Thermal Management
With a thermal resistance of approximately 50°C/W, proper PCB layout is essential for optimal thermal performance. Adequate copper planes for heat dissipation and appropriate airflow should be considered in system design.
Power Supply Decoupling
For reliable operation, place 0.1µF ceramic capacitors close to each VCC pin. This local decoupling reduces power supply noise and ensures stable operation during high-speed configuration transfers.
Signal Integrity
When cascading multiple devices or connecting to FPGAs, maintain proper trace impedance and minimize stub lengths to preserve signal integrity. The 20ns access time requires careful attention to timing margins.
Ordering Information and Package Marking
Part Number Breakdown
XC18V04-VQ44C format:
- XC18V = Product family (In-System Programmable Configuration PROM)
- 04 = Memory density (4 Megabits)
- VQ44 = Package type (44-pin VQFP)
- C = Commercial temperature range (0°C to +70°C)
Common Alternate Markings
The device may also appear with markings like 18V04, XC18V04PC44C, or XC18V04-VQ44C depending on manufacturing date and supplier.
Comparison with Related Devices
XC18V00 Family Members
| Part Number |
Memory Size |
Package Options |
Application |
| XC18V512 |
512 Kilobits |
PLCC, TSOP, VQFP |
Small FPGAs |
| XC18V01 |
1 Megabit |
PLCC, TSOP, VQFP |
Medium FPGAs |
| XC18V02 |
2 Megabits |
PLCC, TSOP, VQFP |
Large FPGAs |
| XC18V04 |
4 Megabits |
VQFP, PLCC |
Very Large FPGAs |
Technical Support and Resources
Documentation
Comprehensive datasheets, application notes, and reference designs are available from AMD/Xilinx and authorized distributors. These resources provide detailed electrical specifications, timing diagrams, and layout guidelines.
Design Tools
The device is compatible with Xilinx Vivado Design Suite and ISE design tools, enabling seamless integration into FPGA development workflows. PROM file generation is supported through standard configuration file outputs.
Development Support
Engineers can access technical forums, application engineers, and development boards to accelerate their design cycles. The widespread adoption of this device family ensures abundant community support and design examples.
Storage and Handling Recommendations
ESD Precautions
As with all semiconductor devices, observe proper electrostatic discharge (ESD) precautions during handling and assembly. Use grounded wrist straps and ESD-safe workstations to prevent device damage.
Moisture Sensitivity
The device has a defined Moisture Sensitivity Level (MSL) rating. Follow proper baking procedures if the moisture indicator card shows exposure beyond acceptable limits before soldering.
Storage Conditions
Store devices in their original packaging at temperatures between -65°C and +150°C. Avoid exposure to excessive humidity or corrosive atmospheres.
Frequently Asked Questions
What is the maximum clock frequency?
The device supports a maximum clock frequency of 33 MHz, suitable for most FPGA configuration requirements.
Can I use this with non-Xilinx FPGAs?
While designed specifically for Xilinx FPGAs, the device may work with other FPGAs supporting serial configuration modes with compatible timing and voltage requirements.
What is the endurance rating?
As a PROM device, the XC18V04-VQ44C supports multiple programming cycles, though specific endurance figures should be confirmed in the datasheet for your application requirements.
Is programming equipment required?
Standard JTAG programming equipment or Xilinx programming cables can be used for in-system programming. No specialized programmers are required.
Conclusion
The XC18V04-VQ44C represents a mature, proven solution for FPGA configuration storage. Its combination of adequate memory capacity, in-system programmability, and reliable operation makes it an excellent choice for engineers designing systems around Xilinx FPGAs. Whether you’re developing telecommunications equipment, industrial controllers, or consumer electronics, this configuration PROM provides the flexibility and reliability your application demands.
For current pricing, availability, and technical specifications, consult authorized AMD/Xilinx distributors. The device’s widespread availability and extensive documentation support ensure smooth integration into your next FPGA-based design project.
