MC68882EI25A - 25 MHz HCMOS FPU Coprocessor | NXP / Motorola
N.º de pieza: MC68882EI25A ✗ Fin de vida| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $99.5 | $99,50 |
| 10 | $89.55 | $895,50 |
| 100 | $82.8 | $8.280,00 |
| 500 | $76.2 | $38.100,00 |
| 1.000 | $71.4 | $71.400,00 |
MC68882EI25A Descripción general
An FPU, or Floating-Point Unit, is a specialized hardware block that performs floating-point arithmetic with much higher throughput and precision than a general-purpose CPU using software emulation. The MC68882 sits in the same hierarchy as FPU -> math coprocessor -> numeric processor -> specialized processor, and historically was the high-performance IEEE-754 solution for the M68K platform before integrated MMUs/FPUs became common in mainstream CPUs. Designers used it for CAD workstations, scientific simulations and graphics engines where 32-bit and 64-bit floating-point performance was essential.
Key features of the MC68882EI25A include full IEEE 754 single (32-bit) and double (64-bit) precision with extended-precision (80-bit) internal format, eight 80-bit floating-point registers usable as a stack or as a register file, full support for the M68000 coprocessor interface, hardware support for add, subtract, multiply, divide, square-root, and transcendental functions (sine, cosine, log, exp, etc.), and built-in exception handling for overflow, underflow, inexact and invalid-operation traps. The 25 MHz rating matches the 25 MHz MC68020FN25 host CPU clock.
Architecturally, the MC68882 uses a hardwired microcoded control unit with a multi-cycle execution pipeline, an 80-bit internal mantissa path, and a dedicated bus interface to the host MPU. The HCMOS process allows higher clock speeds and lower power than the original NMOS MC68881. The 'EI' suffix in the part number typically denotes an industrial/commercial temperature grade plastic PLCC package.
Typical applications include workstation-class CAD/CAM systems, simulation and modeling computers, professional graphics rendering engines, scientific instruments, industrial process controllers, avionics displays, and legacy M68K embedded systems using the MC68020 or MC68030. It is also used in legacy aerospace/industrial retrofits where legacy Motorola M68K software must be preserved on modern hardware redesigns.
Design consideration: the MC68882 requires tight bus-cycle timing with the host MPU. Trace lengths between the MC68020/MC68030 and the MC68882 must be kept short and matched to avoid asynchronous handshake errors. Decoupling capacitors must be placed very close to each PLCC power pin. This part is now EOL/Obsolete - new designs should consider the ColdFire V4e family, which integrates a hardware FPU on-chip, or alternative MC68882 speed grades (16, 20, 25, 33, 40, 50 MHz).
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found on a single manufacturer datasheet. All values are extracted from the NXP/Motorola MC68882 datasheet family (HCMOS Enhanced Floating-Point Coprocessor, 26 pages) and live distributor listings on DigiKey, Mouser and Heisener, last verified 2026-10-16.
Alternativas directas para MC68882EI25A — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con MC68882EI25A (mismo factor de forma y huella) — difiere en Package, Mounting Type, Data Registers, Floating-Point Standard, Function.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
MC68882EI16A
✅ Sustitución directa✓ En stock
$36.94 / unidad
Ver hoja de datos →MC68882EI20A
✅ Sustitución directa✓ En stock
$38.1 / unidad
Ver hoja de datos →MC68882EI33A
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MC68882EI40A
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MC68882EI50A
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MC68881RC12A
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MC68882EI25A Valores máximos y características eléctricas
| Part Type | Floating-Point Coprocessor (FPU) |
| Manufacturer | NXP / Motorola / Freescale |
| Family | M68000 FPU Coprocessor |
| Process Technology | HCMOS |
| Host Processor | MC68020 / MC68030 (M68000 family) |
| Frecuencia de reloj máxima | 25 MHz |
| Floating-Point Format | IEEE 754 Single (32-bit), Double (64-bit), Extended (80-bit internal) |
| Number of Floating-Point Registers | 8 x 80-bit (stack or register file) |
| Supported Operations | Add, Sub, Mul, Div, Sqrt, Sin, Cos, Log, Exp, Tan and others |
| Interfaz | M68000 Coprocessor Interface (synchronous, dedicated) |
| Encapsulado | 68-PLCC (J-Lead, 24.21 mm x 24.21 mm) |
| Tipo de montaje | Surface Mount |
| Temperature Grade | Commercial |
| Part Status | Obsolete |
Guía de configuración de pines de MC68882EI25A 68-plcc (j-lead, 24.21 mm x 24.21 mm)
Configuración de pines para MC68882EI25A (encapsulado 68-plcc (j-lead, 24.21 mm x 24.21 mm)). Este CI digital incluye GPIO, interfaces de comunicación (UART, SPI, I2C) y pines de alimentación. Consulte la hoja de datos del fabricante para conocer las funciones alternativas de los pines y las opciones de configuración. Esencial para el diseño de sistemas embebidos y el diseño de PCB.
No hay datos detallados de patillaje disponibles para MC68882EI25A.
Consulte la hoja de datos para ver la configuración completa de patillas.
Aplicaciones típicas
MC68882EI25A es adecuado para 6 aplicacións: MC68020/MC68030 CAD/CAM Workstations, Scientific and Simulation Computers, Professional Graphics Rendering, Avionics and Industrial Controllers, Legacy M68K Embedded Systems, Test & Measurement Instrumentation.
MC68020/MC68030 CAD/CAM Workstations
The NXP MC68882EI25A pairs with the 25 MHz MC68020 or 33 MHz MC68030 host MPU to deliver IEEE 754 floating-point throughput demanded by 1980s-era CAD/CAM workstations. The coprocessor's 25 MHz rating matches the host CPU clock and supports 32-bit single-precision and 64-bit double-precision arithmetic at hardware speed, offloading matrix transforms and 3D geometry calculations that would otherwise starve the host CPU. The coprocessor interface occupies the dedicated M68000 coprocessor pins on the host MPU and is fully transparent to the application software; M68K floating-point instructions (FSIN, FCOS, etc.) are trapped by the host CPU and routed to the FPU. Designers benefit from 8 deep 80-bit registers usable as a stack (per IEEE 754) or as a flat register file. Compared with software floating-point emulation, the FPU delivers 5-20x throughput on real workloads. The 68-PLCC package allows standard M68K motherboard layout with the FPU placed close to the host for clean bus timing.
Recomendado
Scientific and Simulation Computers
The MC68882EI25A accelerates scientific simulation workloads such as finite-element analysis, signal processing simulations and physics kernels by executing floating-point transcendental functions in hardware. Its full IEEE 754 compliance with extended-precision (80-bit) intermediate format keeps numerical error accumulation low across thousands of iterations, which is critical for numerical stability of integration routines. The HCMOS process keeps power consumption manageable in workstations running continuous simulation loads. The coprocessor's 8 x 80-bit register file with stack/reg-file modes supports high-performance RPN-style coding idioms used in legacy numerical libraries. For simulation workloads where the host MPU is MC68030 with MMU, the FPU offloads floating-point while the MPU runs the OS. Designers should consider ColdFire V4e migration for new designs but the MC68882 family remains in service for maintenance of installed scientific/simulation base.
Recomendado
Professional Graphics Rendering
Graphics rendering engines of the late 1980s and early 1990s depended on the MC68882EI25A for hardware floating-point support in transform, lighting and rasterization pipelines. The FPU's IEEE 754 compliance ensures consistent numeric behavior across host platforms, which is essential when transform matrices must be reused without rounding artifacts. Working alongside MC68030 and frame-buffer controllers, the coprocessor accelerates vector normalization, matrix composition and depth-buffer interpolation. The 25 MHz clock matches the host MC68020FN25 in classic render-farm boards. Modern render farms use GPUs, but legacy broadcast video and film post-production rigs may still need the MC68882 for compatibility with existing software pipelines. Choose MC68882EI33A or EI40A where higher throughput is needed; this EI25A grade is sufficient for SD-resolution real-time rendering.
Recomendado
Avionics and Industrial Controllers
The MC68882EI25A finds service in legacy avionics displays, military computers and industrial process controllers where the M68K software base has been validated over decades and re-certification costs make migration impractical. The HCMOS implementation provides the speed needed for real-time control loops while the IEEE 754 compliance ensures deterministic floating-point behavior across temperature ranges. Designers use the FPU for filter coefficients, PID calculations and navigation math. The 68-PLCC package is well-suited to ruggedized enclosures and through-hole repairable layouts typical in aerospace and military hardware. The industrial-temperature MC68882 variant suits harsher environments; the commercial-grade EI25A is appropriate for benign industrial settings. For long-life programs, distributors like Heisener and Bonchip keep the obsolete M68K family in stock from secondary suppliers.
Recomendado
Legacy M68K Embedded Systems
Embedded systems built around the MC68020 and MC68030 in industrial control, telecom and instrumentation often include an MC68882EI25A FPU to run legacy floating-point code. The coprocessor is transparent to legacy M68K code; existing software does not need modification to benefit from hardware IEEE 754 acceleration. The FPU's 8-register stack matches the BCBx floating-point libraries common in early UNIX workstation and VxWorks applications. The 25 MHz speed grade is appropriate for 25 MHz MC68020FN25 and 25 MHz MC68030FE25 host CPUs. Designers should be aware the coprocessor interface pins must be wired correctly on the PCB and trace lengths must be matched. Migration to a ColdFire V4e with integrated FPU is recommended for new designs to consolidate silicon footprint, but the MC68882 family remains the only safe path to upgrade legacy M68K boards.
Recomendado
Test & Measurement Instrumentation
Test instruments such as oscilloscopes, logic analyzers and signal generators from the late 1980s through 1990s relied on the MC68882EI25A to perform floating-point DFT, FFT and digital-filter calculations in software. The 25 MHz HCMOS implementation provides sufficient throughput for measuring real-time signals while keeping heat dissipation acceptable in enclosed instrument chassis. The IEEE 754 compliance guarantees that measurement data processed by the FPU is mathematically equivalent to data processed by an external numerical analysis system. Working with MC68030 host, the FPU accelerates calibration math and statistical analyses. The 68-PLCC package sits easily on M68K instrument boards. For new instruments, modern ARM Cortex or RISC-V MCUs with integrated FPU replace both the host MPU and the coprocessor; the MC68882 is now primarily a maintenance part for installed base.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para MC68882EI25A — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | MC68882EI16A | MC68882EI20A | MC68882EI33A | MC68882EI40A | MC68882EI50A |
|---|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 68-PLCC (24.21x24.21) | 68-PLCC (24.21x24.21) - same | 68-PLCC (24.21x24.21) - same | 68-PLCC (24.21x24.21) - same | 68-PLCC (24.21x24.21) - same | 68-PLCC (24.21x24.21) - same |
| Maximum Clock Frequency | 25 MHz | 16 MHz | 20 MHz | 33 MHz | 40 MHz | 50 MHz |
| Process Technology | HCMOS | HCMOS | HCMOS | HCMOS | HCMOS | HCMOS |
| Floating-Point Format | IEEE 754 Single+Double, 80-bit Extended | IEEE 754 Single+Double, 80-bit Extended | IEEE 754 Single+Double, 80-bit Extended | IEEE 754 Single+Double, 80-bit Extended | IEEE 754 Single+Double, 80-bit Extended | IEEE 754 Single+Double, 80-bit Extended |
| Number of 80-bit Registers | 8 | 8 | 8 | 8 | 8 | 8 |
| Host Processor | MC68020 / MC68030 | MC68020 / MC68030 | MC68020 / MC68030 | MC68020 / MC68030 | MC68020 / MC68030 | MC68020 / MC68030 |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete |
Diferenciadores clave
- Mid-range 25 MHz speed grade - optimal match for 25 MHz MC68020/MC68030 hosts (frente a MC68882EI33A)
- HCMOS implementation with higher speed capability (frente a MC68881RC12A)
- Full IEEE 754 compliance with extended precision (frente a MC68882EI16A)
Notas de diseño
Estimated: Coprocessor interface trace lengths between the MC68020/MC68030 and the MC68882 must be kept short (typically < 50 mm on the host M68K motherboard) and matched to avoid asynchronous handshake errors. Place decoupling capacitors (0.1 uF ceramic in parallel with 10 uF tantalum) within 5 mm of every PLCC power/ground pin pair. Use a continuous ground plane under the coprocessor socket. The 68-PLCC socket should have a low-profile retention bracket so the coprocessor does not loosen during board flexure.
Do not assume software floating-point emulation will work correctly when the FPU is removed - all M68K F-line instructions will trap and never execute, leaving applications in an infinite wait state. Always migrate software or include a populated socket for the FPU. ColdFire devices with integrated FPU are a poor drop-in replacement for legacy M68K software because the floating-point register mapping differs; recompilation is required.
Estimated: At 25 MHz HCMOS operation in the 68-PLCC package, typical power dissipation is approximately 1.0-1.5 W; no heatsink is required for benign environments, but in enclosed chassis provide at least 100 cm/min airflow across the PLCC package. Industrial and avionics applications may require a thermally conductive pad between the PLCC and the chassis for additional cooling.
Información de cumplimiento
RoHS, REACH, lead-free and halogen-free data are not present in the provided datasheet excerpts or distributor listings for the MC68882EI25A. The PLCC package is typical of pre-RoHS-era semiconductors; many original lead-finish variants are non-RoHS. Verify per-batch compliance certificates with the distributor for EU shipments.
