The XC18V04VQ44C is a high-performance 4-megabit in-system programmable configuration PROM designed specifically for Xilinx FPGA configuration storage and reprogramming. This advanced 3.3V flash-based memory device offers engineers a reliable, cost-effective solution for storing FPGA bitstreams in industrial, automotive, telecommunications, and consumer electronics applications.

XC18V04VQ44C Overview and Key Features

The XC18V04VQ44C belongs to the XC18V00 series of configuration PROMs manufactured by Xilinx (now AMD). This device provides exceptional flexibility with dual configuration modes, JTAG programmability, and robust endurance specifications that meet demanding application requirements.

Primary Features of XC18V04VQ44C

• 4-Megabit Memory Capacity: Stores complete FPGA configuration bitstreams
• 3.3V Operating Voltage: Direct compatibility with modern FPGA families
• In-System Programmable: Reprogram via standard 4-pin JTAG interface
• 20,000 Program/Erase Cycles: High endurance for frequent updates
• 20-Year Data Retention: Long-term reliability for critical applications
• IEEE 1149.1 Boundary-Scan Support: Simplified testing and programming

XC18V04VQ44C Technical Specifications

Understanding the complete specifications helps engineers integrate this configuration PROM effectively into their designs.

Electrical Specifications

Physical Specifications

Operating Conditions

XC18V04VQ44C Configuration Modes

The XC18V04VQ44C supports multiple configuration modes to accommodate various system architectures and design requirements.

Serial Configuration Mode

In Master Serial Mode, the FPGA generates the configuration clock (CCLK) that drives the PROM. Data transfers through the single DATA (D0) pin connected to the FPGA DIN pin. This mode supports clock frequencies up to 33 MHz, making it ideal for space-constrained designs.

In Slave Serial Mode, an external oscillator provides the configuration clock for both the PROM and FPGA, offering greater timing flexibility.

Parallel Configuration Mode (SelectMAP)

For applications requiring faster configuration times, the XC18V04VQ44C supports Parallel Mode using the D0-D7 data pins. This mode achieves data transfer rates up to 264 Mb/s at 33 MHz, significantly reducing FPGA boot times.

JTAG Programming Interface

The XC18V04VQ44C features full IEEE 1149.1 Boundary-Scan (JTAG) compliance, enabling convenient in-system programming without removing the device from the PCB.

JTAG Pin Assignments

Programming Options

Engineers can program the XC18V04VQ44C using several methods:

1. Xilinx iMPACT Software: Direct programming through download cables
2. Vivado Design Suite: Integrated programming environment
3. Third-Party JTAG Tools: Compatible development systems
4. Microprocessor Interface: Custom programming solutions

Device Cascading for Larger Configurations

When a single 4Mbit PROM cannot accommodate the complete FPGA bitstream, multiple XC18V04VQ44C devices can be cascaded together.

Cascading Method

The CEO (Chip Enable Output) pin of one device connects to the CE (Chip Enable Input) of the next device in the chain. All DATA outputs and clock inputs interconnect across the chain. This architecture supports:

• Unlimited cascading depth
• Mixed device densities (XC18V04, XC18V02, XC18V01, XC18V512)
• Compatibility with XC17V00 OTP PROMs

Compatible Xilinx FPGA Families

The XC18V04VQ44C configuration PROM supports a wide range of Xilinx FPGA families:

XC18V04VQ44C Applications

This versatile configuration PROM serves numerous industries and applications:

Telecommunications and Networking

Network equipment manufacturers utilize the XC18V04VQ44C for configuring FPGAs in routers, switches, base stations, and communication infrastructure. The in-system programmability enables field updates without hardware modifications.

Industrial Automation and Control

Factory automation systems, PLCs, and industrial controllers benefit from the device’s wide temperature range and high reliability. The 20,000 program/erase cycles support frequent firmware updates during development and deployment.

Automotive Electronics

Advanced driver assistance systems (ADAS), infotainment units, and in-vehicle networking applications leverage the XC18V04VQ44C for reliable FPGA configuration in demanding automotive environments.

Consumer Electronics

Set-top boxes, digital displays, gaming consoles, and smart home devices use this PROM for efficient, low-power FPGA configuration storage.

Aerospace and Defense

The robust specifications and long data retention make the XC18V04VQ44C suitable for avionics, satellite systems, and military-grade electronics requiring proven reliability.

Ordering Information

XC18V00 Series Comparison

Design Considerations

Power Supply Requirements

Connect VCCINT pins to a stable 3.3V supply with adequate decoupling capacitors (0.1µF ceramic recommended near each power pin). The 5V-tolerant I/O pins accept signals from 5V, 3.3V, and 2.5V systems without level shifters.

PCB Layout Guidelines

• Place decoupling capacitors close to power pins
• Maintain short, direct traces for JTAG signals
• Follow standard surface mount soldering profiles
• Ensure proper thermal management for industrial applications

Conclusion

The XC18V04VQ44C delivers a proven, reliable solution for Xilinx FPGA configuration storage. With its 4-megabit capacity, flexible configuration modes, JTAG programmability, and robust specifications, this in-system programmable PROM meets the demands of diverse applications from consumer electronics to aerospace systems.