AMD XC18V02VQ44I

Overview

XC18V02VQ44I from Xilinx is a 2-Mbit in-system programmable configuration PROM for Xilinx FPGAs, operating at 3.3V with industrial temperature range (–40°C to +85°C), supporting serial (up to 33 MHz) and parallel (up to 264 Mb/s) configuration modes, and featuring IEEE 1149.1 JTAG boundary-scan for programming and verification in embedded FPGA systems.

For engineers reviewing the XC18V02VQ44I datasheet, pinout, applications, or equivalent options, this device serves as a reprogrammable nonvolatile memory solution for FPGA bitstream storage, requiring attention to CE/OE/RESET timing, JTAG CONFIG initiation, cascading CEO chaining, and VQ44 package layout constraints.

Technical Context

The XC18V02VQ44I implements a flash-based memory array with dual-mode interface logic: serial mode uses D0 only with CCLK-driven addressing, while parallel mode activates D0–D7 with byte-wide data output synchronized to CCLK. Its internal address counter increments on each valid rising CCLK edge when CE is low and OE/RESET is high.

JTAG TAP controller supports mandatory instructions (BYPASS, EXTEST, SAMPLE/PRELOAD) and XC18V00-specific CONFIG command that pulses CF pin low to reset and initiate FPGA configuration; IDCODE register reports 05025093h or 05035093h depending on silicon revision, confirming identity and family compliance.

Key Specifications

Pinout & Package

XC18V02VQ44I is housed in a 44-pin Very Thin Quad Flat Pack (VQFP) package, RoHS-compliant, with 0.8 mm pitch and 10 mm × 10 mm body size. Pin functions are validated per DS026 (v4.1) Table 1 and VQ44 top-view diagram.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC18V02PC44I, XC18V02VQ44I offers superior thermal dissipation and board-space efficiency; compared with XC18V04VQ44I, it provides optimal cost/performance balance for mid-range FPGAs without over-provisioning memory.

Availability

XC18V02VQ44I is available at Aetrix Electronics and suitable for industrial automation, aerospace avionics, medical imaging, test equipment, and FPGA-based embedded systems requiring stable component supply across extended product lifecycles.

Supply support for XC18V02VQ44I 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 since 1984.

The XC18V00 series was designed specifically to provide in-system reprogrammable nonvolatile configuration memory for Xilinx FPGAs, emphasizing JTAG integration, industrial reliability, and flexible interface modes.

FAQ

What is the memory capacity of the XC18V02VQ44I?

The XC18V02VQ44I has a total memory capacity of 2,097,152 bits (2 Mbit), sufficient to store the full configuration bitstream for Xilinx FPGAs such as the XC2V250 or XC2S200. This capacity is fixed and not expandable; it is implemented using Xilinx's proprietary flash process optimized for endurance and retention.

Does the XC18V02VQ44I support both serial and parallel configuration modes?

Yes, the XC18V02VQ44I supports dual configuration modes: serial mode (using D0 only, up to 33 MHz) and parallel mode (using D0–D7, up to 264 Mb/s). Mode selection is controlled via a user-accessible register programmed through JTAG using Xilinx iMPACT software; serial mode is the factory-default setting.

How does the JTAG CONFIG instruction work on the XC18V02VQ44I?

The JTAG CONFIG instruction on the XC18V02VQ44I pulses the CF pin low for 300–500 ns, which must be connected to the FPGA's PROGRAM pin to initiate a hardware reset and subsequent configuration cycle. This function is implemented in the TAP controller and requires no external components, enabling fully software-controlled FPGA reconfiguration.

Can multiple XC18V02VQ44I devices be cascaded for larger bitstreams?

Yes, XC18V02VQ44I devices can be daisy-chained using the CEO output of one device to drive the CE input of the next. The CLK and DATA lines are shared across all devices in the chain. Cascading preserves timing integrity and allows storage of bitstreams exceeding 2 Mbit, such as those required for XC2V1000 or larger FPGAs.

What is the purpose of the OE/RESET pin on the XC18V02VQ44I?

The OE/RESET pin on the XC18V02VQ44I is a bidirectional open-drain terminal that holds the internal address counter in reset and places all DATA outputs in high-impedance state when driven low. It is typically connected to the FPGA's INIT pin to synchronize PROM reset with FPGA initialization, ensuring deterministic configuration startup.