The XC17256EPC20C is a high-performance, one-time programmable (OTP) serial configuration PROM manufactured by Xilinx (now AMD). This 256Kb memory device is specifically designed to store and deliver configuration bitstreams for Xilinx FPGA devices, making it an essential component for embedded systems, industrial automation, telecommunications equipment, and aerospace applications.

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XC17256EPC20C Product Overview

The XC17256EPC20C belongs to the XC1700E family of serial configuration PROMs, offering reliable non-volatile storage for FPGA configuration data. With its 20-pin PLCC package and 5V operation, this device provides a cost-effective solution for storing large FPGA configuration bitstreams while maintaining excellent data retention over a guaranteed 20-year lifespan.

This configuration PROM supports both Master Serial and Slave Serial configuration modes, enabling flexible integration with various Xilinx FPGA families including Spartan, Virtex, and XC4000 series devices.

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XC17256EPC20C Technical Specifications

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XC17256EPC20C Pinout Configuration

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XC17256EPC20C Key Features and Benefits

One-Time Programmable Non-Volatile Memory

The XC17256EPC20C provides permanent, secure storage of FPGA configuration data. Once programmed, the bitstream cannot be altered, ensuring design security and preventing unauthorized modifications to your FPGA configuration.

Simple FPGA Interface Design

This serial configuration PROM requires only one user I/O pin for interfacing with the FPGA, simplifying PCB layout and reducing overall system complexity. The straightforward connection scheme minimizes design time and potential points of failure.

Cascadable Architecture for Extended Storage

Multiple XC17256EPC20C devices can be concatenated using the CEO (Cascade Enable Output) to drive the CE input of subsequent PROMs. This cascading capability allows designers to store longer configuration bitstreams or multiple configurations for various FPGA devices.

Programmable Reset Polarity

The XC17256EPC20C offers programmable reset polarity (active High or active Low), ensuring compatibility with different FPGA families and system requirements without additional external logic.

Fast Configuration Support

As part of the XC17256E series, this device supports fast configuration mode, enabling rapid FPGA boot-up times essential for time-critical applications and systems requiring quick initialization.

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XC17256EPC20C Electrical Characteristics

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XC17256EPC20C Compatible FPGA Families

The XC17256EPC20C configuration PROM is compatible with numerous Xilinx FPGA device families:

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XC17256EPC20C Configuration Modes

Master Serial Mode

In Master Serial configuration mode, the FPGA generates the configuration clock (CCLK) that drives the XC17256EPC20C PROM. After a short access time following the rising clock edge, data appears on the DATA output pin connected to the FPGA DIN input. The FPGA generates the appropriate number of clock pulses to complete configuration, then disables the PROM.

Slave Serial Mode

When operating in Slave Serial mode, both the XC17256EPC20C PROM and the target FPGA receive clock signals from an external source. This mode enables synchronized configuration of multiple devices or external control over the configuration timing.

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XC17256EPC20C Package Information

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XC17256EPC20C Ordering Information

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XC17256EPC20C Application Notes

Design Implementation Guidelines

When implementing the XC17256EPC20C in your FPGA configuration circuit, ensure the VPP pin is connected directly to VCC during normal read operations. Leaving VPP floating may result in unpredictable, temperature-dependent behavior that complicates debugging.

Programming Support

The XC17256EPC20C can be programmed using Xilinx Alliance or Foundation software packages, which compile FPGA design files into standard HEX format compatible with most commercial PROM programmers. Leading programmer manufacturers provide comprehensive support for this device family.

Power Supply Considerations

For optimal performance and reliability, use a well-regulated 5V power supply with adequate decoupling capacitors placed close to the VCC and GND pins. A 0.1µF ceramic capacitor in parallel with a 10µF electrolytic capacitor is recommended.

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Why Choose XC17256EPC20C for Your FPGA Design?

The XC17256EPC20C serial configuration PROM delivers the perfect combination of reliability, security, and ease of use for FPGA configuration storage. Its proven 20-year data retention guarantee, simple interface requirements, and compatibility with a wide range of Xilinx FPGA families make it an ideal choice for both new designs and legacy system maintenance.

Whether you’re developing industrial control systems, telecommunications equipment, automotive electronics, or aerospace applications, the XC17256EPC20C provides the dependable configuration storage your FPGA designs demand.

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Frequently Asked Questions About XC17256EPC20C

What is the XC17256EPC20C used for?

The XC17256EPC20C is a serial configuration PROM designed specifically to store and deliver configuration bitstreams to Xilinx FPGA devices. It enables automatic loading of FPGA configurations at power-up.

Can multiple XC17256EPC20C devices be used together?

Yes, multiple devices can be cascaded by connecting the CEO output of one PROM to the CE input of the next. All clock inputs and DATA outputs in the chain are interconnected, allowing storage of larger bitstreams.

What is the difference between XC17256EPC20C and XC17256EPCG20C?

The XC17256EPCG20C is the lead-free (RoHS compliant) version of the XC17256EPC20C, featuring identical electrical specifications but using environmentally compliant packaging materials.

How long does the XC17256EPC20C retain programmed data?

The XC17256EPC20C guarantees a minimum of 20 years of data retention under normal operating conditions.