The XC4085XLA-9HQ240I is a high-density, low-power field-programmable gate array (FPGA) from Xilinx’s XC4000XLA series. Designed for demanding industrial and embedded applications, this device delivers 85,000 logic gates, advanced I/O flexibility, and robust performance in a compact 240-pin HQFP package. Whether you’re developing telecommunications equipment, signal processing systems, or industrial control logic, the XC4085XLA-9HQ240I offers the programmable fabric and reliability needed to get the job done.
For engineers looking to explore the full range of Xilinx FPGA solutions, this product represents one of the most capable devices in the XC4000XLA family.
XC4085XLA-9HQ240I Key Specifications at a Glance
| Parameter |
Value |
| Manufacturer |
Xilinx (AMD) |
| Part Number |
XC4085XLA-9HQ240I |
| Family |
XC4000XLA |
| Logic Gates |
85,000 |
| Configurable Logic Blocks (CLBs) |
1,296 |
| Maximum User I/O Pins |
166 |
| Package Type |
HQFP (Heat Slug Quad Flat Pack) |
| Pin Count |
240 |
| Speed Grade |
-9 |
| Operating Temperature Range |
–40°C to +100°C (Industrial) |
| Supply Voltage (VCC) |
2.5V (XLA core) |
| I/O Voltage |
3.3V tolerant |
| Configuration Interface |
Slave Serial, Master Serial, SelectMAP, JTAG |
| Internal RAM |
Yes (CLB-based distributed RAM) |
| RoHS Compliant |
Yes |
What Is the XC4085XLA-9HQ240I?
The XC4085XLA-9HQ240I belongs to Xilinx’s mature XC4000XLA product family, which was widely adopted throughout the late 1990s and 2000s for high-volume industrial and embedded designs. The “XLA” suffix denotes the eXtended Low-power Architecture variant, offering reduced core voltage (2.5V) compared to earlier XC4000E/XL devices, while maintaining full backward design compatibility.
The “-9” speed grade indicates a 9 ns pin-to-pin logic delay, suitable for moderately high-frequency logic designs. The “HQ240” refers to the 240-pin HQFP package, and the trailing “I” confirms the industrial temperature grade (–40°C to +100°C), making this part well-suited for environments with wide thermal variation.
XC4085XLA-9HQ240I Architecture Overview
Configurable Logic Blocks (CLBs)
The heart of any Xilinx XC4000XLA FPGA is its array of Configurable Logic Blocks (CLBs). The XC4085XLA-9HQ240I contains 1,296 CLBs, each consisting of:
- Two 4-input function generators (LUTs) capable of implementing any 4-variable Boolean function
- One 3-input function generator for additional combinational logic
- Two flip-flops (D-type) with independent clock enable and set/reset controls
- Fast carry and arithmetic logic for efficient adder and counter implementation
- Support for distributed RAM and shift register configurations
This CLB structure enables highly flexible digital logic implementation, from simple glue logic to complex state machines and arithmetic circuits.
I/O Blocks (IOBs)
The device provides 166 user-accessible I/O pins, each connected to a dedicated I/O Block (IOB). Key IOB features include:
- Programmable input/output drive strength
- Optional on-chip pull-up and pull-down resistors
- Input delay elements for setup time management
- Compatibility with 3.3V LVTTL and LVCMOS logic standards
- 5V tolerance on select pins (input-only)
Routing Architecture
| Resource |
Description |
| Local routing |
Short-distance connections within CLB clusters |
| Direct connects |
Fast CLB-to-CLB connections without global routing delay |
| Long lines |
Horizontal and vertical lines spanning the full device |
| Global clock buffers |
4 dedicated global clock distribution networks |
| 3-state buffers |
On-chip bidirectional bus support |
XC4085XLA-9HQ240I Electrical Characteristics
Absolute Maximum Ratings
| Parameter |
Min |
Max |
Unit |
| Core Supply Voltage (VCCINT) |
–0.5 |
3.0 |
V |
| I/O Supply Voltage (VCCO) |
–0.5 |
4.0 |
V |
| Input Voltage |
–0.5 |
VCCO + 0.5 |
V |
| Storage Temperature |
–65 |
+150 |
°C |
| Junction Temperature |
– |
+125 |
°C |
DC Characteristics (Typical, VCC = 2.5V, 25°C)
| Parameter |
Symbol |
Min |
Typical |
Max |
Unit |
| Output High Voltage |
VOH |
2.4 |
– |
– |
V |
| Output Low Voltage |
VOL |
– |
– |
0.4 |
V |
| Input High Voltage |
VIH |
2.0 |
– |
– |
V |
| Input Low Voltage |
VIL |
– |
– |
0.8 |
V |
| Quiescent Supply Current |
ICCQ |
– |
25 |
75 |
mA |
| Output Drive Current (per pin) |
IOH/IOL |
– |
±12 |
– |
mA |
Speed Grade and Timing Performance
The -9 speed grade of the XC4085XLA-9HQ240I offers a balance between cost, power consumption, and performance. Faster speed grades (e.g., -7, -6) are available for higher-frequency designs, while -9 suits the majority of control-plane and moderate datapath applications.
Typical Timing Parameters (Commercial/Industrial)
| Path |
Delay |
| CLB to CLB (fast connect) |
~1.0 ns |
| CLB to CLB (general routing) |
~3.5–7.0 ns |
| Setup time (flip-flop) |
~3.5 ns |
| Clock-to-output (flip-flop) |
~5.0 ns |
| Pin-to-pin combinational |
~9.0 ns |
| Global clock buffer delay |
~1.5 ns |
Note: Actual timing depends on design implementation, routing, and temperature. Always verify with Xilinx ISE timing analysis.
Package Information: 240-Pin HQFP
The XC4085XLA-9HQ240I is housed in a 240-pin HQFP (Heat Slug Quad Flat Pack) package, also referred to as HQ240. This package is designed for surface-mount assembly on standard PCBs.
Package Dimensions
| Parameter |
Value |
| Package Type |
HQFP-240 |
| Body Size |
28mm × 28mm |
| Lead Pitch |
0.5mm |
| Lead Count |
240 |
| Height (seated) |
~3.8mm |
| Exposed Thermal Pad |
Yes (heat slug) |
| PCB Footprint |
QFP-240 compatible |
The integrated heat slug improves thermal dissipation, helping maintain junction temperature within safe limits even under sustained high-logic-utilization workloads.
Configuration Modes
The XC4085XLA-9HQ240I supports multiple configuration modes, giving system designers flexibility in how the FPGA is programmed at power-up:
| Mode |
Description |
Use Case |
| Master Serial |
FPGA drives a serial PROM |
Standalone self-booting systems |
| Slave Serial |
External controller sends bitstream serially |
Multi-FPGA daisy-chain configuration |
| SelectMAP (Slave Parallel) |
8-bit parallel configuration bus |
Fast configuration, microprocessor-driven |
| JTAG (Boundary Scan) |
IEEE 1149.1 compliant |
In-system programming, debug, board test |
JTAG support also enables in-circuit debugging and boundary scan testing, which is valuable for board bring-up and production testing.
Industrial Temperature Grade: –40°C to +100°C
The trailing “I” in the part number confirms this is an industrial-grade component, guaranteed to operate reliably across a junction temperature range of –40°C to +100°C. This makes it suitable for:
- Outdoor telecommunications and networking equipment
- Factory automation and industrial control systems
- Automotive test and measurement instruments
- Military-adjacent and rugged computing platforms
Commercial-grade variants (without the “I” suffix) are typically rated 0°C to +85°C and are not recommended for environments with cold-start requirements or elevated ambient temperatures.
Typical Application Areas
The XC4085XLA-9HQ240I has been widely used across multiple industries and application domains:
#### Telecommunications
- Line card logic in SDH/SONET equipment
- Protocol interface bridging (T1/E1, ATM, Ethernet)
- Alarm and status monitoring circuits
#### Industrial Automation
- PLC I/O expansion and logic sequencing
- Motor drive control logic
- Field bus protocol termination (PROFIBUS, CANbus)
#### Signal Processing
- Real-time FIR/IIR filter implementation
- FFT pre-processing front ends
- Custom datapath acceleration
#### Embedded Systems
- Custom CPU/peripheral bus logic
- Glue logic between processors and memory/peripherals
- FPGA-based state machines
#### Test & Measurement
- Stimulus generation and data capture
- Protocol emulation
- Automated test equipment (ATE) logic
Comparison: XC4085XLA vs. Related Xilinx XC4000XLA Devices
| Part Number |
Logic Gates |
CLBs |
Max I/O |
Package Options |
Speed Grades |
| XC4028XLA |
28,000 |
484 |
112 |
HQ240, PQ240 |
-6, -7, -9 |
| XC4044XLA |
44,000 |
784 |
124 |
HQ240, PQ240 |
-6, -7, -9 |
| XC4085XLA |
85,000 |
1,296 |
166 |
HQ240 |
-7, -9 |
| XC40150XV |
150,000 |
2,304 |
256 |
BG432, HQ240 |
-6, -07, -09 |
The XC4085XLA occupies the upper end of the XC4000XLA family, providing significantly more logic capacity than the XC4028XLA and XC4044XLA while remaining pin-compatible with the same HQ240 footprint — a major advantage for board re-use and design scalability.
Design Tools and Software Support
The XC4085XLA-9HQ240I is supported by Xilinx ISE Design Suite (Internet Systems Environment), specifically ISE version 14.x and earlier. Note that this device is not supported in Vivado, which targets newer 7-Series and UltraScale devices.
Recommended Design Flow
- HDL Entry — VHDL or Verilog using ISE Project Navigator or third-party tools (Mentor, Synopsys)
- Synthesis — XST (Xilinx Synthesis Technology) or Synplicity Synplify
- Implementation — Map, Place & Route within ISE
- Timing Analysis — TRACE (Timing Reporter and Circuit Evaluator)
- Simulation — ISim or ModelSim for functional and timing simulation
- Bitstream Generation — Generate .bit file for FPGA configuration
- Programming — iMPACT tool via JTAG or third-party programming hardware
Ordering Information
| Parameter |
Details |
| Full Part Number |
XC4085XLA-9HQ240I |
| Manufacturer |
Xilinx / AMD |
| Manufacturer Part Number |
XC4085XLA-09HQ240I |
| Package |
240-HQFP |
| Speed Grade |
-9 |
| Temperature Grade |
Industrial (–40°C to +100°C) |
| Lead-Free / RoHS |
Yes |
| Moisture Sensitivity Level (MSL) |
MSL 3 (168 hours floor life after opening) |
| Minimum Order Quantity |
1 |
Frequently Asked Questions (FAQ)
Q: Is the XC4085XLA-9HQ240I still in production? A: The XC4000XLA family is considered a mature/legacy product line. While Xilinx (now AMD) no longer actively promotes it, authorized distributors and component brokers continue to stock and supply this part for maintenance and legacy design purposes.
Q: Can the XC4085XLA-9HQ240I be used in a new design today? A: For new designs, Xilinx’s Artix-7 or Spartan-7 families offer superior performance, density, and tool support. The XC4085XLA is recommended only for replacement/maintenance of existing legacy PCB designs.
Q: What programmer do I need to configure the XC4085XLA-9HQ240I via JTAG? A: The Xilinx Platform Cable USB II or Digilent JTAG-HS2 are compatible programming cables, used alongside the Xilinx iMPACT software.
Q: Is the XC4085XLA pin-compatible with the XC4028XLA in HQ240 package? A: Yes. Both devices share the same HQ240 footprint, allowing board-level upgrades from lower-density to higher-density parts without PCB redesign, though the bitstream and configuration will be different.
Q: What is the difference between the “XL” and “XLA” variants? A: XC4000XL operates at 3.3V core voltage, while XC4000XLA operates at 2.5V core voltage for lower power consumption. Both support 3.3V I/O. XLA devices are not backward-compatible at the bitstream level with XL.
Summary
The XC4085XLA-9HQ240I is a proven, high-gate-count FPGA for industrial and embedded applications demanding reliability across wide temperature ranges. With 85,000 logic gates, 166 user I/O pins, full JTAG support, and a compact 240-pin HQFP surface-mount package, it remains a go-to choice for maintaining legacy systems or finalizing designs originally conceived on the XC4000XLA platform. Its industrial temperature rating, 2.5V low-power core, and multiple configuration mode options make it a versatile component for control-plane and datapath logic alike.
