The XC17S20PD8I is a high-performance serial configuration PROM manufactured by Xilinx (now AMD). This 174K-bit one-time programmable (OTP) memory device is specifically designed to store configuration bitstreams for Xilinx FPGA devices, particularly the Spartan and Spartan-XL series. With its industrial temperature rating and reliable 5V operation, the XC17S20PD8I has become a trusted solution for FPGA configuration in demanding applications.

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XC17S20PD8I Product Overview

The XC17S20PD8I belongs to the XC17Sxx family of configuration PROMs, offering engineers an easy-to-use and cost-effective method for storing FPGA configuration data. This serial PROM provides seamless integration with Xilinx Spartan FPGAs, supporting both Master Serial and Slave Serial configuration modes.

Key Features of XC17S20PD8I

• 174K-bit serial configuration memory for 20,000 system gate FPGA logic
• 5V operating voltage for compatibility with legacy systems
• Industrial temperature range (-40°C to +85°C)
• 8-pin PDIP package for easy PCB integration
• One-time programmable (OTP) technology
• Guaranteed 20-year data retention
• Low-power CMOS EPROM process

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XC17S20PD8I Technical Specifications

Electrical Specifications

Environmental Specifications

Package Information

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XC17S20PD8I Pin Configuration

Pinout Description

Pin Functions Explained

DATA Pin

The DATA pin provides serial configuration data output. When either CE or OE is inactive, this pin enters a high-impedance state. During programming operations, the DATA pin functions as an I/O pin.

CLK Pin

The clock input controls the internal address counter. Each rising edge on the CLK pin increments the address counter, advancing to the next data bit for output.

RESET/OE Pin

This dual-function pin provides reset and output enable functionality. The polarity is programmable, supporting both active-High and active-Low configurations for compatibility with different FPGA solutions.

CEO Pin

The Chip Enable Output facilitates cascading multiple PROMs together. When one PROM completes its configuration data, the CEO signal activates the next PROM in the chain.

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XC17S20PD8I Applications

Primary Applications

The XC17S20PD8I serial configuration PROM is optimized for configuring Xilinx Spartan and Spartan-XL FPGA devices in the following applications:

• Telecommunications equipment – Base stations, routers, and networking hardware
• Industrial automation – PLCs, motor controllers, and process control systems
• Consumer electronics – Set-top boxes, digital displays, and audio/video equipment
• Automotive systems – Infotainment, ADAS, and body control modules
• Medical devices – Diagnostic equipment and patient monitoring systems
• Military and aerospace – Avionics, radar systems, and secure communications

Compatible FPGA Devices

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XC17S20PD8I Configuration Modes

Master Serial Mode

In Master Serial mode, the FPGA generates the configuration clock that drives the XC17S20PD8I PROM. After each rising clock edge, data appears on the PROM DATA output pin, which connects directly to the FPGA’s DIN pin. The FPGA automatically generates the appropriate number of clock pulses to complete configuration. Once configuration is complete, the FPGA disables the PROM to conserve power.

Slave Serial Mode

In Slave Serial mode, both the PROM and FPGA receive clock signals from an external source. This mode is useful for multi-device configurations or when precise timing control is required. The external clock source must provide the correct number of clock cycles to complete the configuration sequence.

Cascading Multiple PROMs

The XC17S20PD8I supports cascading multiple devices for larger configuration storage or multiple bitstreams. The CEO output connects to the CE input of the following device, while clock inputs and DATA outputs are interconnected across all PROMs in the chain. All devices in the XC17Sxx family are compatible and can be cascaded together.

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XC17S20PD8I Programming Information

Programming Requirements

Programming Workflow

1. Design Compilation – Use Xilinx ISE or Alliance software to compile the FPGA design
2. File Generation – Generate standard HEX format configuration file
3. Programmer Setup – Load the HEX file into a compatible PROM programmer
4. Device Programming – Program the XC17S20PD8I with the configuration bitstream
5. Verification – Verify the programmed data against the original file

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XC17S20PD8I Part Number Decoder

Understanding the Part Number

Available Package Options

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XC17S20PD8I Design Considerations

PCB Layout Guidelines

• Place the PROM close to the target FPGA to minimize trace lengths
• Use proper decoupling capacitors (0.1µF ceramic) near VCC pins
• Ensure clean ground connections with minimal inductance
• Route clock and data signals as controlled impedance traces
• Avoid routing high-speed signals near the PROM interface

Power Supply Requirements

• Provide stable 5V ±5% power supply
• Include bulk capacitance (10µF minimum) for transient response
• Use ferrite beads if sharing power with noisy digital circuits
• Ensure proper power sequencing with the target FPGA

Reset Circuit Design

• Connect RESET/OE to FPGA INIT pin with pull-up resistor
• Select appropriate reset polarity based on system requirements
• Allow adequate reset deassertion time for reliable configuration

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XC17S20PD8I Ordering Information

Standard Ordering Part Numbers

Package Marking

Due to the compact package size, device marking uses abbreviated codes:

• The “XC” prefix is omitted
• Package code is simplified
• Full part number available in documentation

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XC17S20PD8I vs Alternative Configuration Solutions

Comparison with Other Configuration Options

When to Choose XC17S20PD8I

The XC17S20PD8I is ideal when:

• Production volumes require cost-effective configuration storage
• The FPGA design is finalized and won’t require updates
• Industrial temperature operation is required
• Simple, reliable configuration is preferred
• Legacy 5V system compatibility is needed

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Frequently Asked Questions About XC17S20PD8I

What FPGA devices are compatible with the XC17S20PD8I?

The XC17S20PD8I is specifically designed for Xilinx Spartan and Spartan-XL FPGA families. It can configure devices with up to 20,000 system gates, including the XCS05, XCS10, XCS20, and their XL variants.

Can the XC17S20PD8I be reprogrammed?

No, the XC17S20PD8I is a one-time programmable (OTP) device. Once programmed, the configuration data cannot be changed. For applications requiring field updates, consider flash-based configuration solutions like the XCF series.

How do I cascade multiple XC17S20PD8I devices?

Connect the CEO output of the first PROM to the CE input of the second PROM. Tie all CLK inputs together and connect all DATA outputs together. The PROMs will automatically sequence during configuration.

What is the maximum clock frequency for configuration?

The XC17S20PD8I supports clock frequencies up to 10 MHz, enabling fast configuration times. The actual configuration time depends on the bitstream size and clock frequency used.

Is the XC17S20PD8I RoHS compliant?

Yes, the “D” suffix in the part number indicates lead-free (Pb-free) construction. The XC17S20PD8I complies with RoHS directives for environmental compliance.

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Conclusion

The XC17S20PD8I serial configuration PROM delivers a proven, cost-effective solution for storing Xilinx FPGA configuration bitstreams. With its industrial temperature rating, reliable OTP technology, and simple 8-pin interface, this device remains a popular choice for embedded systems requiring dependable FPGA configuration. Whether designing telecommunications equipment, industrial controls, or consumer electronics, the XC17S20PD8I provides the reliability and performance needed for successful FPGA-based designs.