Introduction
Programmable Logic Devices (PLDs) let engineers implement custom digital logic without committing to a full-custom ASIC flow. From simple SPLDs/GALs to CPLDs and low-density FPGAs, PLDs enable rapid iteration, predictable timing, long-lifecycle maintenance, and cost control across industrial control, automotive, communications, and embedded systems.
For buyers and engineers planning device selection or migration, see our topic hub: PLD programmable logic device. For a concise definition and taxonomy, refer to Wikipedia: Programmable logic device.
Working Principle (SPLD → CPLD → low-density FPGA)
CPLDs rely on product-term macrocells with deterministic timing and non-volatile configuration; many low-density FPGAs use LUT fabrics with richer routing and optional PLLs, block RAM, and on-chip oscillators. Selection hinges on I/O count, instant-on behavior, timing determinism, power, package, toolchain longevity, and DFT features (e.g., JTAG/IEEE 1149.1).
- Configuration & non-volatility: CPLDs are typically flash/EEPROM-based and instant-on; many FPGAs are SRAM-based and need external configuration unless using flash-based families.
- Timing model: CPLDs favor fixed, shallow routing for predictable propagation delay; LUT fabrics offer flexibility but rely on STA-driven closure.
- Lifecycle & supply: Longevity, temp grade, and multi-source availability are critical for industrial/automotive deployments.
Model Overview (one per brand; full part numbers)
The table lists six widely used PLD/low-density FPGA devices from different vendors.
| Model (Full PN) | Vendor | Fabric Style | Nominal Resources | Package | Highlights |
|---|---|---|---|---|---|
| XC2C256-7TQG144C | AMD Xilinx (CoolRunner-II) | CPLD, product-term macrocells | ~256 macrocells, ~118 I/O | TQFP-144, commercial temp | Low power, instant-on, deterministic timing for glue logic and bridging |
| EPM570T144C5N | Intel (Altera MAX II) | Flash-based CPLD-class | ~440 macrocells, ~116 I/O | TQFP-144 | Non-volatile “instant-on” control/bridge device with UFM |
| LCMXO2-7000HC-6BG332I | Lattice (MachXO2) | Flash-based FPGA (CPLD-like use) | ~6.8k LUTs, high I/O density | FBGA-332, industrial temp | On-chip oscillator, rich I/O—ideal for I/O expansion and control |
| ATF1508AS-10AC100 | Microchip (Atmel CPLD) | CPLD, product-term macrocells | ~128 macrocells, up to ~84/100 pins family | TQFP-100 | Classic 5V-friendly series for legacy maintenance and drop-in replacements |
| CY37256P208-125NI | Infineon Cypress (Ultra37000) | CPLD, product-term macrocells | ~256 macrocells, 208 pins | QFP-208 | ISR™ in-system reprogrammable, great for wide parallel buses |
| A3P060-1FG144I | Microsemi (Actel ProASIC3) | Flash-based FPGA | ~60k system gates, ~96 I/O | FBGA-144, industrial temp | Non-volatile, instant-on—well-suited for harsh industrial control |
Detailed Model Analysis (Part 1)
XC2C256-7TQG144C — Function Overview
CoolRunner-II emphasizes ultra-low static power and deterministic timing. Typical roles include decoders, state machines, bus bridging, and interface consolidation—especially where instant-on matters.
Package & Electrical Characteristics
TQFP-144 eases four-layer routing; core voltage around 1.8 V (family dependent). Multi-standard I/Os simplify mixed-level systems.
Performance & Calibration
Pin-to-pin delays are in single-digit nanoseconds typical. Constrain product-term depth and leverage global clock/reset for predictable closure. Verify worst-case paths with static timing margins.
Application Scenarios
- Parallel-to-serial/serial-to-parallel glue logic
- Legacy bus recreation and address decoding
- Low-power wake/sleep gating
EPM570T144C5N — Function Overview
MAX II combines non-volatile, instant-on behavior with practical control-plane resources. Common uses: MCU bus expansion, address decoding, simple protocol bridges.
Package & Electrical Characteristics
TQFP-144 is rework-friendly. JTAG (IEEE 1149.1) and multi-voltage I/Os support robust production test and field updates; UFM can store IDs/calibration constants.
Performance & Calibration
Apply CDC synchronizers for cross-domain signals; configure UFM write-protection; maintain boundary-scan vectors for manufacturing.
Application Scenarios
- Human–machine interface scanning and indicators
- Voltage/level alignment between SoCs and peripherals
- Instant-on gatekeeping/safety interlocks
LCMXO2-7000HC-6BG332I — Function Overview
MachXO2 blends CPLD-like simplicity with small-FPGA flexibility. On-chip oscillator and rich I/Os fit backplane management, I/O expansion, and light protocol bridging.
Package & Electrical Characteristics
FBGA-332 provides high I/O density; HC (3.3 V) variants interface well with legacy backplanes/industrial modules.
Performance & Calibration
Favor synchronous pipelines; limit long combinational chains. Use the on-chip oscillator for watchdog/brownout handlers and plan I/O banks with power-noise budget in mind.
Application Scenarios
- Hot-swap/power sequencing and board management
- GPIO fan-out/fan-in and simple SERDES fan-in control
- Industrial interlocks and panel logic
Transition to Part 2
In Part 2 we continue with deeper analysis of ATF1508AS-10AC100, CY37256P208-125NI, and A3P060-1FG144I, then provide comparison tables, selection guidance, and practical bring-up and calibration checklists.
Detailed Model Analysis (Part 2)
ATF1508AS-10AC100 — Function Overview
A classic 5 V CPLD with ~128 macrocells that excels at replacing PAL/GAL/TTL logic in legacy industrial ecosystems; strong value for life-extension programs.
Package & Electrical Characteristics
TQFP-100; 5 V tolerance simplifies direct connection to older backplanes, relays, and optocouplers. JTAG enables in-system programming and field serviceability.
Performance & Calibration
Design for debounce and robust edge detection; account for relay flyback and noise with timing margins and proper IO protection.
Application Scenarios
- Refits of aging production controllers (drop-in logic consolidation)
- 5 V industrial interface aggregation
- Legacy equipment life extension (LTS)
CY37256P208-125NI — Function Overview
Ultra37000 family, ~256 macrocells in a large-pin-count package, emphasizing ISR™ in-system reprogramming and wide fan-in/fan-out.
Package & Electrical Characteristics
QFP-208 offers abundant I/O for parallel buses; good compatibility with 3.3 V/5 V environments (per family options).
Performance & Calibration
Use global clock/reset and partition product terms to minimize critical paths; add input synchronizers and error detection across board-to-board boundaries.
Application Scenarios
- Backplane/frame arbitration and selection
- Acquisition cards (triggering and gating)
- Chained GPIO matrices and timing grids
A3P060-1FG144I — Function Overview
ProASIC3 is a flash FPGA: instant-on, non-volatile configuration, and inherently low configuration risk—great for deterministic control and state machines in harsh environments.
Package & Electrical Characteristics
FBGA-144; industrial temperature support; internal clock networks reduce skew, while flash technology helps with low static power.
Performance & Calibration
Prefer single-clock-domain designs and CDC synchronizers; enforce IO filtering and robust ESD/EMC constraints at the board level.
Application Scenarios
- Protocol adaptation and monitoring on high-speed backplanes
- Safety-related state machines (configuration retained at power loss)
- Multi-rail power sequencing and fault tolerance
Comparison Tables & Performance Summary
Table A — Selection Snapshot
| Use Case | Recommended Model | Why |
|---|---|---|
| Legacy 5 V industrial retrofit | ATF1508AS-10AC100 | 5 V ecosystem, instant-on, simple field maintenance via JTAG |
| High-I/O backplane control | CY37256P208-125NI | 208 pins, ISR™ for in-system updates |
| Low-power glue logic with deterministic timing | XC2C256-7TQG144C | Low power, predictable pin-to-pin timing |
| I/O expansion & light protocol bridges | LCMXO2-7000HC-6BG332I | On-chip oscillator, non-volatile, rich I/O |
| Harsh environment, instant-on fabric | A3P060-1FG144I | Flash FPGA, industrial temp range |
| Panel/indicator control + ID storage | EPM570T144C5N | Non-volatile, UFM for parameters/serials |
Table B — Design & Timing Focus
| Model | Timing Model | Configuration | Bring-up Tips |
|---|---|---|---|
| XC2C256-7TQG144C | Product-term macrocells | Non-volatile, instant-on | Limit combinational depth; use global clock/reset |
| EPM570T144C5N | Macrocell + flash control | Non-volatile | Protect UFM; maintain boundary-scan vectors |
| LCMXO2-7000HC-6BG332I | LUT fabric | Non-volatile (flash) | Bank planning; validate on-chip oscillator tolerance |
| ATF1508AS-10AC100 | Product-term macrocells | Non-volatile | Design for EMC; protect against relay flyback |
| CY37256P208-125NI | Product-term macrocells | Non-volatile; ISR™ | Define in-system update & rollback procedures |
| A3P060-1FG144I | LUT fabric | Non-volatile (flash) | Constrain CDC; isolate clock domains |
Table C — Application Mapping
| Application | Shortlist | Rationale |
|---|---|---|
| Power sequencing & interlocks | LCMXO2-7000HC-6BG332I, A3P060-1FG144I | On-chip clocking, non-volatile config, flexible routing |
| Legacy bus recreation | ATF1508AS-10AC100, XC2C256-7TQG144C | 5 V compatibility or low-power deterministic timing |
| High-pin backplane control | CY37256P208-125NI | Abundant I/O, in-system reprogramming |
| MCU peripheral expander | EPM570T144C5N | Non-volatile with UFM for IDs/config |
Design Recommendations
- Requirement-to-device mapping: Fix I/O count and instant-on need first; then balance deterministic timing versus LUT flexibility.
- Tooling & longevity: Verify compiler, download cable, and fixture availability for full lifecycle; record backup programming flows.
- Maintainability: For ISR™/JTAG-capable parts, implement version signatures, rollback paths, and field verification scripts.
Integration & Calibration Techniques
- Establish a unified clocking strategy with CDC audit; cap combinational depth.
- Design safe erase/program flows and robust reset for non-volatile parts.
- Freeze boundary-scan vectors and fixtures during DVT to ensure repeatable production test.
Conclusion
The six full part numbers above span classic 5 V CPLDs to flash-based, instant-on FPGAs—covering most PLD use cases. Aligning selection with your environment, supply chain, and maintenance plan—and following the timing/integration guidance—can reduce risk and total lifecycle cost. For pricing, alternates, and lead-time assessments, contact YY-IC集成电路供应商.