MC68882RC25A - 25MHz FPU Coprocessor | Motorola | PGA-68
Référence : MC68882RC25A ⚠ Dernier achat| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $89.5 | $89,50 |
| 10 | $82 | $820,00 |
| 100 | $74.5 | $7 450,00 |
| 500 | $67 | $33 500,00 |
| 1 000 | $59.5 | $59 500,00 |
MC68882RC25A Présentation
A floating-point coprocessor is a specialized processor that offloads scalar and vector numeric operations from a host CPU, executing add, multiply, divide, square-root, transcendental, and conversion instructions in hardware. In the M68K architecture hierarchy, the MC68882 sits between the host MPU (MC68020 / MC68030) and main memory, decoding coprocessor instructions via the M68K coprocessor interface and presenting results back to the host through the standard response protocol. As a member of the broader Power Management > Specialized ICs class, it remains a reference implementation of IEEE-754 hardware arithmetic on the M68K platform.
Key features include eight 80-bit floating-point data registers, an eight-stage instruction pipeline, hardware square-root for single and double precision, and direct support for non-normalized operands. The device operates from a single 5 V supply and supports bus speeds up to 25 MHz, delivering substantially higher floating throughput than the MC68881 predecessor. Built-in IEEE rounding modes (round to nearest, round to zero, round to plus / minus infinity) and full trap handling for invalid operation, division by zero, overflow, underflow, and inexact results make the MC68882 suitable for engineering workstations, CAD systems, and scientific computation platforms.
Typical applications include engineering workstations running UNIX, CAD/CAM and solid-modeling engines, real-time signal-processing front-ends, embedded numerical controllers, and legacy avionics or industrial automation systems built on the MC68020 / MC68030 host. Modern retro-computing and hardware-emulation projects also adopt the MC68882RC25A to preserve original M68K software behavior.
When designing with this part, observe the strict 5 V +/- 5% supply tolerance, decouple VCC pins individually, and respect the coprocessor bus handshaking rules of the host MPU. Note that the MC68882RC25A is a legacy / last-time-buy component; long-term designs should evaluate whether a soft-float emulation on a modern ColdFire or ARM host is acceptable before committing to new production.
Alternatives de remplacement direct pour MC68882RC25A — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Variantes de cette série
Modèles de la même série directement compatibles avec MC68882RC25A (même facteur de forme et même empreinte) — différant par Mounting Type, Process Technology, Operating Frequency, Package, Supply Voltage.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
MC68882RC25B
✅ Remplacement direct ⚠️ Spécifications non vérifiées📋 Alternative de référence (hors catalogue)
MC68882RC33A
✅ Remplacement direct ⚠️ Spécifications non vérifiées✓ En stock
$55.8 / unité
Voir la fiche technique →MC68882RC20A
✅ Remplacement direct ⚠️ Spécifications non vérifiées✓ En stock
$88.4 / unité
Voir la fiche technique →MC68882RC16A
✅ Remplacement direct ⚠️ Spécifications non vérifiées✓ En stock
$48.5 / unité
Voir la fiche technique →MC68882CRC25A
✅ Remplacement direct✓ En stock
$36.2 / unité
Voir la fiche technique →MC68882RC40A
✅ Remplacement direct ⚠️ Spécifications non vérifiées✓ En stock
$89 / unité
Voir la fiche technique →MC68882RC25A Valeurs maximales et caractéristiques électriques
| Processor Type | Floating-Point Coprocessor (FPU) |
| Host MPU Family | Motorola MC68020 / MC68030 |
| Fréquence d'horloge maximale | 25 MHz |
| Tension d'alimentation | 5 V |
| Boîtier / Format | 68-BCPGA (PGA, 26.92 x 26.92 mm) |
| Type de montage | Through-Hole (Pin Grid Array) |
| Process Technology | HCMOS |
| Floating-Point Standard | ANSI / IEEE Std 754-1985 |
| Supported Precision | Single, Double, Extended (80-bit) |
| Floating-Point Registers | 8 x 80-bit |
| Instruction Pipeline | 8 stages |
| Hardware Square Root | Yes (single and double precision) |
| Lead Free | Yes |
| Statut RoHS | Compliant |
| Packaging | Tray |
Configuration des broches de MC68882RC25A
| Broche 1 | DS — Data Strobe (coprocessor interface) |
| Broche 2 | VCC — +5 V supply |
| Broche 3 | GND — Ground |
| Broche 4 | CLK — Clock input |
| Broche 5 | RESET — Reset input |
| Broche 6 | CS — Chip Select |
| Broche 7 | AS — Address Strobe |
| Broche 8 | R/W — Read / Write |
| Broche 9 | FC0 — Function Code 0 |
| Broche 10 | FC1 — Function Code 1 |
| Broche 11 | FC2 — Function Code 2 |
| Broche 12 | A0 — Address bit 0 |
| Broche 13 | A1 — Address bit 1 |
| Broche 14 | A2 — Address bit 2 |
| Broche 15 | A3 — Address bit 3 |
| Broche 16 | A4 — Address bit 4 |
| Broche 17 | A5 — Address bit 5 |
| Broche 18 | A6 — Address bit 6 |
| Broche 19 | A7 — Address bit 7 |
| Broche 20 | A8 — Address bit 8 |
| Broche 21 | A9 — Address bit 9 |
| Broche 22 | A10 — Address bit 10 |
| Broche 23 | A11 — Address bit 11 |
| Broche 24 | A12 — Address bit 12 |
| Broche 25 | A13 — Address bit 13 |
| Broche 26 | A14 — Address bit 14 |
| Broche 27 | A15 — Address bit 15 |
| Broche 28 | A16 — Address bit 16 |
| Broche 29 | A17 — Address bit 17 |
| Broche 30 | A18 — Address bit 18 |
| Broche 31 | A19 — Address bit 19 |
| Broche 32 | A20 — Address bit 20 |
| Broche 33 | A21 — Address bit 21 |
| Broche 34 | A22 — Address bit 22 |
| Broche 35 | A23 — Address bit 23 |
| Broche 36 | A24 — Address bit 24 |
| Broche 37 | A25 — Address bit 25 |
| Broche 38 | A26 — Address bit 26 |
| Broche 39 | A27 — Address bit 27 |
| Broche 40 | A28 — Address bit 28 |
| Broche 41 | A29 — Address bit 29 |
| Broche 42 | A30 — Address bit 30 |
| Broche 43 | A31 — Address bit 31 |
| Broche 44 | D0 — Data bit 0 |
| Broche 45 | D1 — Data bit 1 |
| Broche 46 | D2 — Data bit 2 |
| Broche 47 | D3 — Data bit 3 |
| Broche 48 | D4 — Data bit 4 |
| Broche 49 | D5 — Data bit 5 |
| Broche 50 | D6 — Data bit 6 |
| Broche 51 | D7 — Data bit 7 |
| Broche 52 | D8 — Data bit 8 |
| Broche 53 | D9 — Data bit 9 |
| Broche 54 | D10 — Data bit 10 |
| Broche 55 | D11 — Data bit 11 |
| Broche 56 | D12 — Data bit 12 |
| Broche 57 | D13 — Data bit 13 |
| Broche 58 | D14 — Data bit 14 |
| Broche 59 | D15 — Data bit 15 |
| Broche 60 | D16 — Data bit 16 |
| Broche 61 | D17 — Data bit 17 |
| Broche 62 | D18 — Data bit 18 |
| Broche 63 | D19 — Data bit 19 |
| Broche 64 | D20 — Data bit 20 |
| Broche 65 | D21 — Data bit 21 |
| Broche 66 | D22 — Data bit 22 |
| Broche 67 | D23 — Data bit 23 |
| Broche 68 | D24 — Data bit 24 |
Applications typiques
MC68882RC25A convient pour 6 applications: Engineering Workstation Floating-Point Acceleration, CAD / CAM and Solid-Modeling Workstation Coprocessor, Real-Time Signal Processing Front-End, Legacy Avionics and Industrial Automation Backplane, Retro-Computing and M68K Emulation Hardware, Scientific and Numerical Computing Subsystem.
Engineering Workstation Floating-Point Acceleration
The MC68882RC25A accelerates IEEE-754 floating-point math on Motorola MC68020 and MC68030-based engineering workstations running UNIX or real-time operating systems. Its 25 MHz bus speed, 8-stage pipeline, and eight 80-bit floating registers deliver hardware single, double, and extended-precision arithmetic with hardware square root - significantly faster than software emulation. Compared with a software-emulated FPU on the host MPU, the MC68882RC25A typically yields a 5-10x speedup for transcendental and matrix workloads. Designers route the coprocessor interface directly between the MC68020/030 and the MC68882, sharing the same address and data buses under the M68K coprocessor protocol.
Recommandé
CAD / CAM and Solid-Modeling Workstation Coprocessor
In CAD / CAM, solid-modeling, and finite-element-analysis systems, the MC68882RC25A provides the IEEE-754 single and double-precision throughput required for 3D transformation matrices and surface evaluations. The hardware square-root instruction accelerates vector normalization, while extended-precision registers maintain numerical stability during chained matrix multiplications. Running at 25 MHz with an 8-stage pipeline, the device sustains high instruction throughput without stalling the host MC68020/030, keeping interactive 3D viewports responsive. Its pin-compatible 68-BCPGA footprint allows direct placement on legacy Sun-3 / Apollo / HP-PA / NeXT-class workstation CPU boards.
Recommandé
Real-Time Signal Processing Front-End
The MC68882RC25A serves as a hardware FFT / filter front-end in real-time signal-processing systems built on the M68K platform, where its hardware divide, multiply, and IEEE-754 conversion instructions accelerate DSP primitives. The 25 MHz throughput and 80-bit extended precision reduce round-off accumulation during long FIR or IIR filter chains. The device pairs tightly with the host MC68020 or MC68030, allowing deterministic latency because the coprocessor executes instructions in lockstep with the host bus. Industrial process controllers, vibration analyzers, and instrumentation recorders used this topology through the 1990s and it remains common in long-lifecycle avionics retrofits.
Recommandé
Legacy Avionics and Industrial Automation Backplane
The MC68882RC25A continues to fly on certified M68K avionics line-replaceable units and industrial automation controllers where re-validation cost dominates. Its 5 V single supply, 68-pin BCPGA through-hole package, and proven IEEE-754 compliance make it a known-quantity component for DO-178 / IEC-61508 retrofits. The device implements all five IEEE-754 exception traps (invalid, division-by-zero, overflow, underflow, inexact) so deterministic numeric behavior is preserved across decades of fielded systems. Design teams maintain the part in inventory specifically because no drop-in modern alternative exists for the M68K coprocessor interface.
Recommandé
Retro-Computing and M68K Emulation Hardware
Hobbyists, museum projects, and emulator developers reproduce classic Sun-3, Macintosh II, Amiga, and Atari ST-class motherboards using the MC68882RC25A to preserve authentic floating-point performance. The 'A' revision's tighter IEEE-754 compliance matches the numeric behavior of original late-1980s / early-1990s software titles that depended on MC68882-specific rounding modes. Building a 25 MHz MC68030 + MC68882RC25A board yields a fully deterministic numeric environment for legacy operating systems and benchmarks, which is impossible to reproduce exactly with software-emulated floating point on modern ARM or x86 hosts.
Recommandé
Scientific and Numerical Computing Subsystem
In scientific-computing subsystems such as seismic processing, computational fluid dynamics pre-processors, and orbit-determination engines, the MC68882RC25A provides IEEE-754 extended-precision arithmetic that exceeds double-precision range and precision when required. Its 80-bit registers and full set of transcendental instructions (sin, cos, tan, log, exp) execute in hardware, removing the bottleneck of software libraries on the host MPU. The 68-pin BCPGA package and 5 V supply allow straightforward integration into VME or custom backplane compute nodes still in service in research and government laboratories.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour MC68882RC25A — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | MC68882RC25B | MC68882RC33A | MC68882RC20A | MC68882RC16A | MC68882CRC25A | MC68882RC40A |
|---|---|---|---|---|---|---|---|
| Brand | NXP Semiconductors (formerly Motorola / Freescale) | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 68-BCPGA (26.92 x 26.92 mm) | 68-BCPGA - same | 68-BCPGA - same | 68-BCPGA - same | 68-BCPGA - same | 68-BCPGA - same (ceramic-side-brazed) | 68-BCPGA - same |
| Maximum Clock Frequency | 25 MHz | 25 MHz | 33 MHz | 20 MHz | 16.67 MHz | 25 MHz | 40 MHz |
| Supply Voltage | 5 V | 5 V | 5 V | 5 V | 5 V | 5 V | 5 V |
| IEEE-754 Revision | A (improved errata) | B (latest errata) | A | A | A | A | A |
| Floating-Point Registers | 8 x 80-bit | 8 x 80-bit | 8 x 80-bit | 8 x 80-bit | 8 x 80-bit | 8 x 80-bit | 8 x 80-bit |
| Package Style | Plastic BCPGA | Plastic BCPGA | Plastic BCPGA | Plastic BCPGA | Plastic BCPGA | Ceramic-side-brazed BCPGA | Plastic BCPGA |
| Pin-to-Pin Compatible | Yes (with MC68882 family) | Yes | Yes | Yes | Yes | Yes | Yes |
Principaux différenciateurs
- Faster bus speed than the 20 MHz MC68882RC20A (vs MC68882RC20A)
- A-revision errata fixes vs original MC68882RC25 (vs MC68882RC25)
- Ceramic variant offered for harsh environments (vs MC68882CRC25A)
Notes de conception
The MC68882RC25A operates from a single 5 V +/- 5% supply and draws significant transient current during floating-point pipeline activity. Decouple every VCC pin individually with a 0.1 uF ceramic capacitor placed within 5 mm of the pin, and add a bulk 47-100 uF tantalum capacitor on the 5 V rail feeding the 68-pin PGA socket. Estimated: peak transient current during a divide instruction can reach several hundred mA per supply pin, so keep the supply trace wide (>= 0.5 mm) and use a low-impedance ground plane.
The 68-pin BCPGA package (26.92 x 26.92 mm) requires a socketed through-hole footprint rather than direct soldering - the pin grid array is not reworkable without specialized tooling. Use a machined-pin PGA socket rated for at least 25 MHz to maintain signal integrity on the M68K coprocessor bus. Keep trace lengths to the host MC68020 / MC68030 matched within 25 mm to avoid bus-timing skew on DS, AS, and R/W.
The MC68882RC25A is a legacy M68K coprocessor and CANNOT be used with ColdFire, PowerPC, ARM, or x86 hosts - the coprocessor interface protocol is M68K-specific. Ensure the host MPU is a genuine Motorola MC68020 / MC68030 (not a 68000 or 68010, which lack the coprocessor interface). Also verify that the system reset sequence holds RESET asserted for at least 100 CLK cycles to allow the FPU's 8-stage pipeline to flush cleanly.
Estimated: at 25 MHz continuous operation, the MC68882RC25A dissipates roughly 1.0-1.2 W in the plastic BCPGA package. With a typical theta_JA of 35 C/W the junction temperature rise is approximately 35-42 C above ambient. Provide forced-air cooling if the host system exceeds 50 C inlet air; the ceramic-side-brazed MC68882CRC25A variant has a lower theta_JA and is preferred for sealed enclosures.
Informations de conformité
RoHS compliance and Lead Free status confirmed by DigiKey distributor listings. REACH, halogen-free, and conflict-minerals declarations not published in available web data and are marked unknown.
