MC68882CRC25A - 25 MHz FPU Coprocessor, 68-PGA | Motorola
MPN: MC68882CRC25A ✗ Cuối đờiMC68882CRC25A Tóm tắt
What is a floating-point coprocessor? A floating-point coprocessor is a specialized processor that offloads arithmetic-intensive operations (add, subtract, multiply, divide, square root, transcendental functions) from the main CPU. Coprocessors belong to the broader category of arithmetic logic units, processor extensions, and finally semiconductor ICs. The MC68882 specifically extended the M68K CISC architecture with hardware IEEE-754 compliance, which the 68020's built-in FPU lacked for full conformance.
Key features of the MC68882CRC25A include full IEEE 754 conformance with rounding modes (round to nearest, toward zero, toward +inf, toward -inf), extended precision 80-bit registers, complete exception handling with 16 exception vector types, and software-selectable precision control. The 25 MHz speed grade corresponds to a 40 ns cycle time and suits 68020/68030 systems running at the same clock frequency.
Architecturally, the MC68882 uses a 32-bit HCMOS internal data path, an 8-deep instruction prefetch queue, and dedicated hardware for denormalized number handling. The chip communicates with the host through coprocessor interface instructions (cpGen, cpDBcc, cpScc, cpBcc, cpRESTORE, cpSAVE) per the M68K definition, ensuring tight CPU-FPU coupling with zero glue logic required.
Typical applications include legacy UNIX workstations, scientific and engineering workstations running floating-point-intensive CAD/CAE codes, military and aerospace vector graphics systems, and industrial motion-control DSP front-ends. The 68-PGA package was designed for socketed through-hole assembly on early 1990s motherboards and add-in accelerator cards.
When designing with this part, ensure the host CPU is a 68020 or 68030 with coprocessor interface signals properly terminated. The MC68882CRC25A is discontinued (NRND/EOL); verify lifetime-buy requirements with Rochester Electronics, the last authorized distributor, before committing to new designs.
This page synthesizes distributor pricing, drop-in alternative analysis, and practical design notes not found in the original Motorola datasheet, giving engineers sourcing decisions that the manufacturer's product page does not.
Bộ thay thế dễ dàng lắp đặt cho MC68882CRC25A — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với MC68882CRC25A (cùng hình factor và footprint) — khác nhau ở Mounting Type, Process Technology, Architecture, Operating Frequency, Package.
MC68882CRC33A
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MC68882CRC20A
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →MC68882CRC16A
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MC68882RC25
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MC68882CRC25A Tỷ lệ tối đa & tính chất điện
| Part Number | MC68882CRC25A |
| Manufacturer | Motorola Semiconductor Products |
| Product Type | Floating-Point Coprocessor (FPU) |
| Architecture | M68K coprocessor interface, HCMOS |
| Operating Frequency | 25 MHz |
| Floating-Point Throughput | 46 MIPS (peak) |
| Bề rộng đường dữ liệu | 32-bit |
| Internal Registers | 8 x 80-bit floating-point |
| Arithmetic Standard | IEEE 754-1985 (single, double, extended precision) |
| Điện áp cung cấp | 5 V |
| Hộp | 68-PGA (BCPGA, 26.92 x 26.92 mm) |
| Kiểu lắp đặt | Through-Hole (PGA socket) |
| Lead-Free Status | Lead Free |
| Trạng thái RoHS | RoHS Compliant |
| Packaging | Tray |
| Compatible Host CPU | Motorola 68020, 68030 |
| Process Technology | HCMOS |
Hướng dẫn cấu hình chân MC68882CRC25A 68-pga (bcpga, 26.92 x 26.92 mm)
Cấu hình chân cho MC68882CRC25A (68-pga (bcpga, 26.92 x 26.92 mm) gói). IC số này bao gồm chân GPIO, giao diện truyền thông (UART, SPI, I2C) và chân nguồn. Tham khảo tài liệu thông số kỹ thuật của nhà sản xuất để biết các chức năng chân thay thế và tùy chọn cấu hình. Cực kỳ quan trọng cho thiết kế hệ thống tích hợp và lập trình PCB.
Không có dữ liệu chân cụ thể sẵn có cho MC68882CRC25A.
Tham khảo: tài liệu kỹ thuật cho cấu hình chân đầy đủ.
Ứng dụng tiêu biểu
MC68882CRC25A phù hợp cho 6 Áp dụngs: M68K UNIX Workstation Floating-Point Acceleration, Industrial Motion Control and DSP Front-End, Legacy Avionics and Aerospace Vector Graphics, Military Embedded Computing and C4ISR Systems, Classic Macintosh / Amiga / Atari Floating-Point Card, Scientific and Engineering CAD Workstation.
M68K UNIX Workstation Floating-Point Acceleration
The MC68882CRC25A was the standard floating-point accelerator for M68K-based UNIX workstations of the late 1980s and early 1990s. Its 25 MHz throughput and IEEE 754-1985 compliance allow it to execute floating-point-intensive workloads from C compilers (SunOS cc, gcc) at 5-20x the speed of the 68020 software emulation library. Placing the chip in the dedicated coprocessor socket adjacent to the 68020 CPU yields 46 MIPS peak throughput, sufficient for spreadsheet recalculation, CAD wireframe rendering, and scientific data analysis. The 68-pin ceramic PGA package was selected for these workstations to support PGA through-hole soldering and reliable thermal dissipation across 1-2 W continuous operation.
Được đề xuất
Industrial Motion Control and DSP Front-End
The MC68882CRC25A's hardware multiply, divide, and square-root instructions accelerate the inner loops of motor-control and signal-processing kernels running on 68020/68030 industrial controllers. With 80-bit extended precision it can accumulate position-error values without rounding degradation over long time windows - critical for multi-axis CNC machines and robot arm controllers. The 5 V HCMOS design tolerates typical industrial supply rails (-10% / +5%), and the 68-pin ceramic PGA package has the long-term availability required by 15-25 year industrial lifecycle programs. Place the coprocessor on the same board as the host CPU to offload real-time control loops from interrupt latency.
Được đề xuất
Legacy Avionics and Aerospace Vector Graphics
The MC68882CRC25A's full IEEE 754 conformance and extended precision make it suitable for avionics flight management computers and aerospace cockpit display generators where deterministic floating-point arithmetic is required for navigation solutions. The ceramic PGA package was selected for aerospace use due to its hermeticity and resistance to vibration-induced lead fatigue. Combined with the 68030 host, the FPU performs 3D coordinate transformations for synthetic-vision displays at frame rates up to 30 Hz. Note that FAA/EASA-certified designs using this part require DO-254 verification documentation, typically available through Rochester Electronics for qualified aerospace customers.
Được đề xuất
Military Embedded Computing and C4ISR Systems
The MC68882CRC25A appears in legacy ruggedized military computers performing sensor fusion, radar signal processing, and command/control calculations. Its HCMOS technology and ceramic packaging are rated for -55°C to +125°C extended military temperature ranges typical of tactical and ground-mobile applications. The coprocessor accelerates Kalman filter and FFT kernels executed on the host 68020/68030, supporting real-time situational-awareness processing in C4ISR platforms. Long-term availability for defense programs is supported by Rochester Electronics under authorized license from the original Motorola/NXP/Freescale datasheet rights.
Được đề xuất
Classic Macintosh / Amiga / Atari Floating-Point Card
The MC68882CRC25A was offered as an aftermarket floating-point accelerator for classic Macintosh (Mac II, IIx, IIcx, IIfx), Amiga (A2000, A3000, A4000), and Atari Falcon030 platforms. OEMs such as DayStar Digital, Applied Engineering, and MacroSystem Design sold these 25 MHz FPU cards for users running floating-point-intensive applications such as Photoshop filters, LightWave 3D rendering, and audio DSP plug-ins. The 68-pin PGA socket is mounted on a small daughter-card plugged into the host's dedicated coprocessor connector, and the FPU is auto-detected at boot by System 7 / AmigaOS 3.x.
Được đề xuất
Scientific and Engineering CAD Workstation
The MC68882CRC25A's extended 80-bit precision was specifically designed to eliminate intermediate rounding error in CAD wireframe modeling, finite-element mesh refinement, and computational fluid dynamics codes running on M68K workstations (Apollo, HP 9000/400, Sun-3). At 25 MHz the FPU executes double-precision matrix operations approximately 15x faster than the 68020 emulation libraries, enabling interactive rotation and Boolean operations on 3D models. The IEEE 754 conformance ensures numerical reproducibility across workstations and meets the verification requirements for FEM stress-analysis toolchains. Modern replacements would be ColdFire or PowerPC SoCs, but the MC68882CRC25A remains the reference FPU for legacy M68K CAD installations.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho MC68882CRC25A — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | MC68882CRC33A | MC68882CRC20A | MC68882CRC16A | MC68882RC25 |
|---|---|---|---|---|---|
| Brand | Motorola Semiconductor Products | Motorola Semiconductor Products | Motorola Semiconductor Products | Motorola Semiconductor Products | Motorola Semiconductor Products |
| Package | 68-PGA (BCPGA, 26.92 x 26.92 mm) | 68-PGA (BCPGA) - same | 68-PGA (BCPGA) - same | 68-PGA (BCPGA) - same | 68-PGA (BCPGA) - same |
| Operating Frequency | 25 MHz | 33 MHz | 20 MHz | 16 MHz | 25 MHz |
| Supply Voltage | 5 V | 5 V | 5 V | 5 V | 5 V |
| Floating-Point Throughput | 46 MIPS | ~60 MIPS | ~37 MIPS | ~29 MIPS | 46 MIPS |
| Internal Registers | 8 x 80-bit FPR | 8 x 80-bit FPR | 8 x 80-bit FPR | 8 x 80-bit FPR | 8 x 80-bit FPR |
| IEEE 754 Conformance | Full (1985) | Full (1985) | Full (1985) | Full (1985) | Full (1985) |
| Compatible Host CPU | 68020, 68030 | 68020, 68030 | 68020, 68030 | 68020, 68030 | 68020, 68030 |
Bảo phân biệt quan trọng
- Balanced throughput/cost for legacy M68K systems (vsMC68882CRC33A)
- Downward-compatible pin-compatible upgrade path (vsMC68882CRC16A)
- Versus latest 'A' silicon revision (vsMC68882RC25)
Ghi chú thiết kế
The MC68882CRC25A is EOL/NRND. Distributors like Rochester Electronics hold factory-licensed inventory but at premium prices (USD 50+ per unit in qty-1). For new designs, plan a migration path to Freescale/NXP ColdFire MCF548x or MCF547x with integrated FPU. Existing 68020/68030-based designs must secure lifetime-buy quantities from authorized distributors; grey-market stock from other channels may have unknown provenance and counterfeiting risk. Always request Rochester's Certificate of Conformance (CoC) for aerospace/defense builds.
Estimated: At 25 MHz the MC68882CRC25A draws approximately 0.6-0.8 A from a 5 V supply (~3-4 W). Decoupling requires one 0.1 µF ceramic capacitor at each VCC pin plus one bulk 47 µF tantalum at the PGA socket corner, plus a 10 µF electrolytic at board entry. The 68-pin ceramic PGA package has relatively low thermal resistance (~15°C/W) due to ceramic substrate, but sustained FPU activity (FFT, matrix inversion) can push junction temperature to 50-60°C above ambient in sealed enclosures. Provide at least 0.5 sq. in. of inner copper plane area for thermal spread.
Place the MC68882CRC25A within 1 inch (25 mm) of the host 68020 or 68030 to keep the coprocessor interface bus signals short and matched. The dedicated signals PC[0-2], BGACK, DSACKx, and CIP_CLK are timing-critical and require matched-length traces (within 0.5 inch / 12 mm) to avoid coprocessor-bus errors. Use a four-layer PCB with dedicated VCC and GND planes; the HCMOS design is particularly sensitive to ground bounce on the coprocessor interface. Reference the original Motorola MC68882 evaluation board layout for guidance.
Thông tin tuân thủ
Lead-free per Digchip datasheet entry; RoHS compliant per verified data. REACH and halogen-free status not specified in the source data and marked 'unknown'. AEC-Q100 is not applicable for legacy M68K FPU products.
