AMD XC18V512PC20I

Overview

XC18V512PC20I from Xilinx is a 512-kilobit in-system programmable 3.3V configuration PROM for Xilinx FPGAs, supporting serial (up to 33 MHz) and parallel (up to 264 Mb/s) modes, with 20,000 program/erase cycles, industrial temperature range (–40°C to +85°C), and IEEE 1149.1 JTAG compliance. It enables FPGA reconfiguration in embedded control and test equipment.

For engineers reviewing the XC18V512PC20I datasheet, pinout, applications, or equivalent options, key selection criteria include serial/parallel mode flexibility, JTAG-initiated FPGA reset via CF pin, 5V-tolerant I/O, dual supply (3.3V/2.5V output), and cascading capability for multi-FPGA systems.

Technical Context

The XC18V512PC20I implements a flash-based nonvolatile memory architecture with boundary-scan TAP controller for IEEE 1149.1-compliant in-system programming and verification. Its internal address counter increments on CLK rising edge when CE is low and OE/RESET is high.

Configuration sequencing is synchronized to FPGA CCLK in Master Serial/SelectMAP modes or external oscillator in Slave-Parallel/Slave-SelectMAP modes. The CF pin-routed to D4 in 20-pin packages-supports JTAG-triggered FPGA PROGRAM pulse (300–500 ns), enabling remote reconfiguration without power cycle.

Key Specifications

Pinout & Package

XC18V512PC20I uses a 20-pin PLCC (PC20) package with 12 active pins and 8 no-connects. Pin functions are defined per DS026 v4.1 Table 1 and Figure 15.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar configuration PROM applications.

Compared with XC18V512SO20I and XC17V512PC20, the XC18V512PC20I uniquely combines PLCC serviceability, in-system reprogrammability, and JTAG-initiated FPGA reset - making it optimal for prototyping, test infrastructure, and upgradable embedded systems.

Availability

XC18V512PC20I is available at Aetrix Electronics and suitable for industrial motor control, automated test equipment, avionics data acquisition, and medical imaging subsystems requiring stable component supply and long-term obsolescence management.

Supply support for XC18V512PC20I includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Xilinx, now part of AMD, is a pioneer in programmable logic and FPGA technology, delivering high-performance, configurable semiconductor solutions since 1984.

The XC18V00 series was designed specifically to provide reliable, in-system reprogrammable configuration storage for Xilinx FPGA families - addressing needs in development iteration, field upgrade, and secure IP deployment.

FAQ

What configuration modes does the XC18V512PC20I support?

The XC18V512PC20I supports serial (slow/fast) and parallel configuration modes, selectable via JTAG-accessible control register. Serial mode operates up to 33 MHz with single-bit data transfer; parallel mode achieves up to 264 Mb/s at 33 MHz using D0–D7. Default is serial mode; parallel mode must be explicitly enabled in Xilinx iMPACT software before programming.

How is the CF pin implemented on the XC18V512PC20I in the PC20 package?

On the XC18V512PC20I in 20-pin PLCC (PC20) package, the CF (CONFIG) function is routed to pin 7, overriding the default D4 assignment - but only if parallel mode is disabled. This enables JTAG-triggered FPGA PROGRAM pulses (300–500 ns) without requiring additional PCB routing, critical for remote reconfiguration in deployed systems.

Can the XC18V512PC20I be used to configure modern Xilinx FPGA families like Artix or Kintex?

No - the XC18V512PC20I is designed exclusively for legacy Xilinx FPGA families including Spartan-II, Spartan-IIE, Virtex, Virtex-E, and Virtex-II, as documented in DS026 Table 2. It lacks compatibility with 7-series, UltraScale, or newer architectures that require different configuration protocols and voltage levels.

What is the role of the CEO pin in cascaded XC18V512PC20I configurations?

The CEO (Chip Enable Output) pin on the XC18V512PC20I goes Low when its internal address counter reaches terminal count and OE/RESET is High - signaling the end of its bitstream. It directly drives the CE input of the next XC18V512PC20I in the chain, enabling seamless handoff and continuous configuration loading across multiple devices without external logic.

Does the XC18V512PC20I support read protection against unauthorized JTAG access?

Yes - the XC18V512PC20I includes a user-settable read security bit that inhibits JTAG readback of configuration data. When enabled, the internal pattern cannot be read via JTAG; the only way to clear the bit is full device erase. This feature is verified in DS026 Section "Design Security" and Table 3.