AMD XC18V04VQ44C0100

Overview

XC18V04VQ44C0100 from Xilinx is a 4-Mbit in-system programmable configuration PROM designed to store and serially/parallel load bitstreams into Xilinx FPGAs. It supports Master Serial (up to 33 MHz), Slave Parallel (264 Mb/s), JTAG-initiated configuration, and cascading for extended memory. Its 5V-tolerant I/O, industrial temperature range (–40°C to +85°C), and 20,000 program/erase cycles make it suitable for reconfigurable embedded control and prototyping systems.

For engineers reviewing the XC18V04VQ44C0100 datasheet, pinout, applications, or equivalent options, key selection criteria include serial vs. parallel interface timing, CEO daisy-chain capability, JTAG CONFIG instruction support via CF pin, VCCINT/VCCO dual-supply operation, and compatibility with Virtex-II, Spartan-3, and older XCV/XC2S FPGA families.

Technical Context

The XC18V04VQ44C0100 implements a flash-based nonvolatile memory architecture with boundary-scan IEEE 1149.1 compliance and dedicated JTAG CONFIG instruction to pulse the CF pin for FPGA reset-and-configure. Its internal address counter advances on rising CLK edges when CE is low and OE/RESET is high, enabling synchronous data delivery aligned to FPGA CCLK.

It operates in two primary modes: serial (D0 only, 1-bit wide) and parallel (D0–D7, 8-bit wide), selected via JTAG-accessible user control register. The device supports both master-driven (FPGA-generated CCLK) and slave-driven (external oscillator) clocking, with CEO output enabling seamless cascading across multiple PROMs without external logic.

Key Specifications

Pinout & Package

XC18V04VQ44C0100 is packaged in a 44-pin Very Thin Quad Flat Package (VQ44), RoHS-compliant and lead-free. Pin layout follows JEDEC MO-220 standard with 0.8 mm pitch; thermal pad optional per datasheet note.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC18V04PC44C, the XC18V04VQ44C0100 offers identical functionality in a thinner, surface-mount-optimized package with improved thermal dissipation; compared with XC17V04PC44C, it adds full in-system reprogrammability, JTAG control, and configuration security - critical for iterative development and secure deployment.

Availability

XC18V04VQ44C0100 is available at Aetrix Electronics and suitable for industrial control systems, aerospace avionics, automated test equipment, and legacy FPGA migration projects requiring stable component supply and long-term obsolescence management.

Supply support for XC18V04VQ44C0100 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 adaptive computing solutions for aerospace, industrial, and communications markets since 1984.

The XC18V00 series was engineered specifically to provide reliable, reprogrammable configuration storage for Xilinx's Virtex, Spartan, and Vertex FPGA families - emphasizing ease of integration, JTAG accessibility, and industrial-grade endurance.

FAQ

What is the function of the CF pin on the XC18V04VQ44C0100?

The CF (CONFIG) pin on the XC18V04VQ44C0100 is an open-drain output controlled exclusively by the JTAG CONFIG instruction. When executed, it pulses low for 300–500 ns to assert the FPGA's PROGRAM_B pin, triggering a full reset and reconfiguration sequence. This enables remote, software-initiated FPGA reload without host processor involvement or hardware reset lines. The XC18V04VQ44C0100 CF pin must be directly connected to the target FPGA's PROGRAM_B input to function.

Can the XC18V04VQ44C0100 be used with modern Xilinx 7-series FPGAs?

No, the XC18V04VQ44C0100 is not compatible with Xilinx 7-series FPGAs. It was designed for legacy families including Virtex-E, Virtex-II, Spartan-II, Spartan-IIE, and XC2S/XCV devices. 7-series FPGAs require SPI-based configuration PROMs (e.g., Platform Flash XL) or QSPI flash controllers. Using XC18V04VQ44C0100 with a 7-series device will result in failed configuration due to incompatible protocol, voltage signaling, and bitstream format.

How does cascading work with multiple XC18V04VQ44C0100 devices?

Cascading XC18V04VQ44C0100 devices uses the CEO (Chip Enable Output) pin of one PROM to drive the CE (Chip Enable) input of the next. When the first device reaches its terminal count, CEO goes low, enabling the second device's outputs. CLK and D0 (or D0–D7) are wired in parallel across all devices. This allows seamless extension of configuration memory beyond 4 Mbit - e.g., two XC18V04VQ44C0100 units provide 8 Mbit - with no additional control logic or FPGA pin overhead.

What are the power supply requirements for the XC18V04VQ44C0100?

The XC18V04VQ44C0100 requires two independent supplies: VCCINT = 3.3V ±5% for core logic and JTAG controller, and VCCO = 3.3V or 2.5V for I/O buffers. VCCINT pins (17, 35, 38) must be decoupled with 0.1 µF ceramics; VCCO pins (8, 16, 26, 36) require separate decoupling. Inputs are 5V-tolerant, but VCCINT must never exceed 3.6V. Power sequencing requires VCCINT to stabilize before OE/RESET release to ensure proper power-on reset.

Is the XC18V04VQ44C0100 still in production or supported by AMD/Xilinx?

The XC18V04VQ44C0100 is marked "PRODUCT OBSOLETE / UNDER OBSOLESCENCE" per Xilinx DS026 v6.0 (2015). It is no longer manufactured or actively supported by AMD/Xilinx, though Aetrix Electronics maintains legacy inventory and provides traceable, tested units for ongoing production and repair. Designers should plan migration to newer configuration solutions (e.g., Platform Flash XL or Micron serial NOR) for new projects.