The XC17256EPD8C is a high-reliability serial configuration PROM manufactured by Xilinx (now AMD). This 256-Kbit one-time programmable (OTP) memory device is specifically designed to store and load configuration data into Xilinx FPGA devices. Engineers and designers trust the XC17256EPD8C for its robust performance, compact 8-pin PDIP package, and seamless integration with Xilinx FPGA families.
XC17256EPD8C Key Features and Benefits
The XC17256EPD8C configuration PROM delivers exceptional value for FPGA-based system designs. Here’s why this component stands out in the market:
High-Density Configuration Storage
The XC17256EPD8C provides 256 Kbits (32,768 bytes) of non-volatile storage capacity. This memory size perfectly suits small to medium-sized Xilinx FPGA configurations, including the XC4000 and Spartan series devices.
Reliable One-Time Programmable Technology
As an OTP (One-Time Programmable) PROM, the XC17256EPD8C ensures your FPGA configuration remains permanently stored and tamper-resistant. This makes it ideal for production environments where configuration integrity is critical.
Compact 8-Pin PDIP Package
The plastic dual in-line package (PDIP) format offers easy handling, straightforward PCB mounting, and compatibility with standard through-hole assembly processes.
XC17256EPD8C Technical Specifications
| Parameter |
Specification |
| Part Number |
XC17256EPD8C |
| Manufacturer |
Xilinx (AMD) |
| Memory Type |
Serial Configuration PROM |
| Memory Density |
256 Kbit (32K × 8) |
| Programming Type |
OTP (One-Time Programmable) |
| Package Type |
PDIP-8 (Plastic Dual In-Line Package) |
| Pin Count |
8 |
| Supply Voltage (VCC) |
5V |
| Operating Temperature |
0°C to +70°C (Commercial) |
| Data Output |
Serial |
| Interface |
Serial Peripheral Interface (SPI-Compatible) |
| Status |
Legacy / End of Life |
XC17256EPD8C Pin Configuration
Understanding the pin layout is essential for proper PCB design and integration. The table below outlines the XC17256EPD8C pinout:
| Pin Number |
Pin Name |
Function |
| 1 |
DATA |
Serial Data Output |
| 2 |
CLK |
Serial Clock Input |
| 3 |
RESET/OE |
Reset / Output Enable |
| 4 |
CE |
Chip Enable (Active Low) |
| 5 |
CEO |
Chip Enable Output (for daisy-chaining) |
| 6 |
GND |
Ground |
| 7 |
VCC |
Power Supply (5V) |
| 8 |
VPP |
Programming Voltage |
Compatible Xilinx FPGA Families
The XC17256EPD8C configuration PROM is designed to work seamlessly with several Xilinx FPGA product lines:
| FPGA Family |
Compatibility |
Typical Application |
| XC4000 Series |
Full Support |
Industrial Control Systems |
| XC4000E Series |
Full Support |
Telecommunications Equipment |
| XC4000EX Series |
Full Support |
Aerospace Applications |
| Spartan Series |
Full Support |
Consumer Electronics |
| Spartan-II |
Partial Support |
Embedded Systems |
XC17256EPD8C Applications and Use Cases
Industrial Automation Systems
The XC17256EPD8C excels in industrial environments where reliable FPGA boot-up is mandatory. Manufacturing equipment, PLC systems, and motor controllers frequently incorporate this PROM.
Telecommunications Infrastructure
Network switches, routers, and base station equipment leverage the XC17256EPD8C for dependable FPGA configuration storage with minimal component count.
Aerospace and Defense Electronics
Mission-critical systems benefit from the OTP architecture, which prevents accidental reconfiguration and ensures consistent FPGA operation across power cycles.
Legacy System Maintenance
Organizations maintaining older Xilinx FPGA-based systems rely on the XC17256EPD8C as a direct replacement component for field repairs and refurbishment projects.
XC17256EPD8C vs. Alternative Configuration Solutions
| Feature |
XC17256EPD8C (OTP PROM) |
Flash-Based PROM |
External SPI Flash |
| Reprogrammability |
No (One-Time) |
Yes (Limited Cycles) |
Yes (High Cycles) |
| Configuration Security |
High |
Medium |
Low-Medium |
| Cost per Unit |
Low |
Medium |
Low |
| Board Space |
Minimal (8-pin) |
Varies |
Varies |
| Design Complexity |
Low |
Low |
Medium |
| Best For |
Production Systems |
Prototyping |
High-Density FPGAs |
How to Program the XC17256EPD8C
Programming the XC17256EPD8C requires a compatible Xilinx device programmer. Follow these steps for successful configuration:
Step 1: Generate Configuration File
Use Xilinx ISE or Vivado Design Suite to generate the FPGA bitstream file. Export the configuration in PROM-compatible format (.mcs or .exo).
Step 2: Select Programming Hardware
Compatible programmers include the Xilinx HW-130 programmer, third-party universal programmers with XC17256 support, and legacy Xilinx download cables with appropriate adapters.
Step 3: Execute Programming Sequence
Load the configuration file into the programming software, insert the XC17256EPD8C into the programmer socket, and initiate the programming cycle. Verify the programmed data against the source file.
XC17256EPD8C Ordering Information
| Order Code |
Package |
Temperature Range |
Availability |
| XC17256EPD8C |
PDIP-8 |
Commercial (0°C to +70°C) |
Legacy Stock |
| XC17256EPD8I |
PDIP-8 |
Industrial (-40°C to +85°C) |
Limited |
| XC17256EPC8C |
PLCC-20 |
Commercial (0°C to +70°C) |
Legacy Stock |
Frequently Asked Questions About XC17256EPD8C
What does XC17256EPD8C stand for?
The part number breaks down as follows: XC17256 (Xilinx Configuration 256Kbit), E (Commercial grade), PD (PDIP package), 8 (8-pin), C (standard speed grade).
Is the XC17256EPD8C still in production?
The XC17256EPD8C is classified as a legacy component. While Xilinx (AMD) no longer manufactures new units, authorized distributors and specialty suppliers maintain stock for replacement and maintenance applications.
Can I reprogram the XC17256EPD8C?
No. The XC17256EPD8C utilizes OTP (One-Time Programmable) technology. Once programmed, the configuration data cannot be erased or modified. For reprogrammable alternatives, consider flash-based configuration solutions.
What is the maximum clock frequency for the XC17256EPD8C?
The XC17256EPD8C supports serial clock frequencies up to 10 MHz under standard operating conditions, enabling fast FPGA configuration times.
Conclusion: Why Choose the XC17256EPD8C
The XC17256EPD8C remains a trusted solution for Xilinx FPGA configuration storage in production and legacy systems. Its combination of 256-Kbit density, OTP security, compact 8-pin PDIP packaging, and proven reliability makes it the right choice for industrial, telecommunications, and aerospace applications. Whether you’re maintaining existing equipment or sourcing components for specialized projects, the XC17256EPD8C delivers dependable FPGA configuration performance.
