The XC4085XLA-09HQ160I is a high-density, low-power Field Programmable Gate Array (FPGA) from the Xilinx XC4000XLA family, offered in a 160-pin HQFP (Heat-dissipating Quad Flat Package) with a commercial-grade speed rating of -09. Designed for complex digital logic applications, this Xilinx FPGA delivers over 85,000 usable gates combined with advanced routing architecture, making it a reliable solution for telecommunications, industrial control, embedded processing, and signal processing designs.

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XC4085XLA-09HQ160I Overview and Key Features

The XC4085XLA-09HQ160I belongs to Xilinx’s mature XC4000XLA product line, which is widely recognized for its robust configurable logic block (CLB) architecture. The “XLA” designation indicates the extended low-voltage, advanced process node variant, enabling lower power consumption and higher performance compared to earlier XC4000 generations.

Why Choose the XC4085XLA-09HQ160I?

• High Gate Density – 85,000 system gates provide ample resources for complex logic designs
• Low-Voltage Operation – The XLA process delivers reduced core voltage, cutting dynamic power dissipation
• 160-Pin HQFP Package – A compact, surface-mount package suitable for space-constrained PCB layouts
• Industrial Temperature Grade – The “I” suffix denotes an industrial temperature range (–40°C to +85°C), ideal for harsh environments
• -09 Speed Grade – A 9 ns internal logic delay rating balancing performance with power efficiency
• Flexible I/O – Supports multiple I/O standards including LVTTL and LVCMOS

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XC4085XLA-09HQ160I Technical Specifications

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XC4085XLA-09HQ160I Part Number Decoder

Understanding each segment of the part number helps engineers verify compatibility at a glance.

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XC4085XLA-09HQ160I vs. Similar Variants: Speed Grade Comparison

The XC4085XLA is available in multiple speed grades. Choosing the right speed grade is critical for timing closure in high-frequency designs.

Note: Lower speed grade numbers indicate faster devices. The -09 speed grade is well-suited for designs running at frequencies up to ~60–80 MHz.

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XC4000XLA Architecture Deep Dive

Configurable Logic Blocks (CLBs)

The XC4085XLA-09HQ160I features Xilinx’s proprietary CLB structure, each containing:

• Two 4-input Look-Up Tables (LUTs) capable of implementing any combinational Boolean function of up to four variables
• Two edge-triggered flip-flops with dedicated set, reset, and clock enable signals
• Fast carry logic for efficient arithmetic operations
• Internal tri-state buffers for flexible bus architectures

Routing Architecture

The XC4000XLA uses a hierarchical routing structure including:

• Single-length lines for local CLB-to-CLB connections
• Double-length lines for intermediate-distance routing
• Long lines spanning the full device width or height
• Global clock buffers providing low-skew clock distribution to all flip-flops

On-Chip Memory Resources

Distributed RAM is implemented using CLB LUTs, enabling:

• Synchronous single-port and dual-port RAM configurations
• Shift register implementations
• ROM look-up tables

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XC4085XLA-09HQ160I Pin Configuration and Package Details

HQFP-160 Package Outline

Power Supply Pins

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Configuration Methods for XC4085XLA-09HQ160I

The XC4085XLA-09HQ160I supports four FPGA configuration modes, selected via the M0, M1, M2 mode pins:

Recommended Configuration ICs: Xilinx XC17V16 or XC18V01/04 serial configuration PROMs are commonly used with this device.

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Electrical Characteristics

DC Absolute Maximum Ratings

DC Operating Conditions (XLA, VCC = 2.5V ±10%)

AC Timing Characteristics (–09 Speed Grade)

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Applications and Use Cases

The XC4085XLA-09HQ160I is widely deployed across demanding industries where proven, long-lifecycle FPGA solutions are required:

#### Telecommunications Equipment

High-density framing, protocol conversion (SONET/SDH framing logic), and line card control circuitry leverage the device’s large CLB array and fast I/O.

#### Industrial Automation and Control

Motor drive control, PLC logic replacement, and real-time sensor processing benefit from the industrial temperature range (–40°C to +85°C) and reliable CMOS logic architecture.

#### Military and Aerospace (COTS/Legacy Programs)

Legacy defense programs often require long-term supply of proven components. Rochester Electronics provides authorized, fully traceable inventory of XC4085XLA devices for sustainment programs.

#### Signal Processing and DSP

Distributed RAM and fast carry chains enable efficient FIR filter, FFT butterfly, and correlator implementations within the XC4000XLA CLB fabric.

#### Embedded Systems and Prototyping

The XC4085XLA-09HQ160I serves as a prototyping platform for ASIC emulation and embedded logic development, given its mature and well-documented toolchain support.

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Design Tools and Software Support

Important Note: The XC4085XLA-09HQ160I is not supported by Xilinx Vivado. Designers must use ISE 14.7 or earlier for synthesis, implementation, and bitstream generation.

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Ordering Information and Availability

The XC4085XLA-09HQ160I is an end-of-life (EOL) part from AMD/Xilinx. Authorized aftermarket and legacy supply sources include Rochester Electronics, which provides fully traceable, manufacturer-authorized inventory.

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Frequently Asked Questions (FAQ)

#### What is the difference between XC4085XLA-08HQ160I and XC4085XLA-09HQ160I?

The only difference is the speed grade. The -08 variant has an 8 ns internal logic delay, making it slightly faster than the -09 variant (9 ns). Both use the same 160-pin HQFP package, same industrial temperature range, and identical CLB resources. For timing-critical paths, -08 provides more margin; for cost-sensitive or less speed-critical designs, -09 is sufficient.

#### Is the XC4085XLA-09HQ160I still in production?

No. This device is end-of-life (EOL). AMD/Xilinx discontinued new production. However, authorized distributors such as Rochester Electronics maintain traceable legacy inventory to support long-lifecycle applications in defense, industrial, and telecommunications.

#### What configuration PROM is compatible with XC4085XLA-09HQ160I?

The XC17V16, XC17256A, and XC18V01/04 Xilinx serial configuration PROMs are commonly paired with this device. For parallel configuration, standard SPI or parallel flash memory can be used with the SelectMAP interface.

#### Can I replace XC4085XLA-09HQ160I with a modern Xilinx FPGA?

Migration to a modern device such as a Xilinx Spartan-6 or Artix-7 is possible but requires a complete redesign of the PCB (different footprint) and HDL re-synthesis in Vivado. Pin-for-pin drop-in replacements do not exist for this legacy part.

#### What does the “I” suffix mean in XC4085XLA-09HQ160I?

The “I” suffix denotes the Industrial temperature grade, meaning the device is tested and guaranteed to operate correctly across the full –40°C to +85°C ambient temperature range. The “C” suffix (commercial) devices are rated for 0°C to +85°C only.

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Summary

The XC4085XLA-09HQ160I is a proven, high-density FPGA offering approximately 85,000 system gates in a compact 160-pin HQFP surface-mount package. Its XLA low-voltage process (2.5V core), industrial temperature range, and flexible configuration options make it an enduring choice for legacy industrial, telecommunications, and defense applications. While the device is end-of-life from AMD/Xilinx, authorized distributors continue to supply traceable inventory for system sustainment. Engineers evaluating this component should use Xilinx ISE 14.7 for design implementation and consider speed grade, I/O requirements, and supply chain availability when selecting between the -07, -08, and -09 variants.