MC68882EI25AR - 25MHz 68882 FPU Co-Processor | 68-PLCC
MPN: MC68882EI25AR ✗ Akhir HidupMC68882EI25AR Ringkasan
An FPU co-processor is a specialized processor that works in lockstep with a host CPU to execute floating-point instructions in hardware rather than emulating them in software. Within the M68000 ecosystem hierarchy, the MC68882 sits beside the host CPU as an M-class co-processor (companion chip), falling under the broader categories of math co-processor -> co-processor -> specialized IC -> microprocessor peripheral. By handling transcendental functions (sine, cosine, log, exp), IEEE 754 arithmetic, and packed BCD, the 68882 delivered workstation-class numeric performance to 68k-based systems such as the Amiga, Atari, early Macintosh, and various industrial/embedded controllers.
Key features include hardware IEEE 754 single and double precision, eight 80-bit floating-point registers organized as a stack with renaming, fully concurrent execution with the host CPU through the M68000 coprocessor interface, and support for the complete M68000 family F-line instruction set including FMOV, FADD, FMUL, FDIV, FSIN, FCOS, FLOG and FEXP. The 25 MHz suffix (-25) corresponds to a 25 MHz system-clock operation. The PLCC-68 surface-mount package retains the traditional J-lead footprint for easy socket replacement on legacy boards.
The 68882 architecture consists of an instruction-decoder/prefetch unit, an FPU execution datapath, an 80-bit register file, and a bus interface that communicates with the host CPU through the M68000 coprocessor protocol. Unlike modern integrated FPUs, the 68882 occupies a separate socket and is invisible to software once configured - the host CPU decodes F-line opcodes and dispatches them to the co-processor transparently. Internal pipeline overlap allows the host and FPU to run concurrently, hiding latency.
Typical applications include legacy M68020/M68030 workstation upgrades (Amiga 3000/4000, Atari TT/Falcon, early Mac II/Quadra via PDS cards), industrial-control retrofit boards requiring floating-point acceleration, vintage computer restoration projects, and educational/emulation environments studying 68k architecture. Because the part is now in the obsolete/EOL category, it is most often sourced for maintenance of installed bases rather than new design.
A key design consideration when working with this part is that the 68882 must be clocked at the same frequency as, or in lockstep with, the host M68000 CPU; mismatch causes timing violations on the coprocessor handshake. Because the part is obsolete, second-source and franchised stocking distributors are the primary supply channel. Designers should always verify lot traceability and request a manufacturer certificate of conformance when procuring.
This page synthesizes current distributor pricing, parametric comparison with same-family variants, and practical sourcing/design notes not found in the original Motorola/NXP datasheet alone.
Alternatif penggantian untuk MC68882EI25AR — paket yang sama, pin-pada-pin kompatibel. Bagian paket yang berbeda memerlukan kerja ulang PCB diabaikan.
Variasi di dalam seri ini
Model-series yang sama yang kompatibel dengan penggantian MC68882EI25AR (sama faktor bentuk dan footprint) — berbeda di dalam Mounting Type, Floating-Point Standard, Function, Operating Frequency, Package / Case.
MC68882EI16A
✅ Drop-InKontak untuk harga
Lihat Datasheet →MC68882EI20A
✅ Drop-InKontak untuk harga
Lihat Datasheet →MC68882EI33A
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
MC68882EI40A
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
MC68882EI25AR Rating Maksimal & Karakteristik Listrik
| Part Status | Obsolete |
| Type | Floating-Point Co-Processor |
| Series | MC680x0 |
| Nominal Supply Voltage | 5 V |
| Maximum Supply Voltage | 5.25 V |
| Minimum Supply Voltage | 4.75 V |
| Operating Frequency | 25 MHz |
| Maximum Operating Temperature | 70 C |
| Temperature Grade | Commercial |
| Paket / Case | 68-LCC (J-Lead) |
| Supplier Device Package | 68-PLCC (24.21 x 24.21 mm) |
| Tipe Mounting | Surface Mount |
| Terminal Finish | Matte Tin |
| Host CPU Compatibility | MC68020, MC68030, MC68040 |
| Floating-Point Standard | IEEE 754 (single & double precision, 80-bit extended) |
| Application | Math co-processor for 68k family |
Konfigurasi Pin MC68882EI25AR
| Pin produk 1 | GND — Ground |
| Pin produk 2 | DSACK0 — Data transfer and size acknowledge 0 |
| Pin produk 3 | DSACK1 — Data transfer and size acknowledge 1 |
| Pin produk 4 | AVEC — Autovector interrupt request |
| Pin produk 5 | IPL0 — Interrupt priority level 0 |
| Pin produk 6 | IPL1 — Interrupt priority level 1 |
| Pin produk 7 | IPL2 — Interrupt priority level 2 |
| Pin produk 8 | VCC — +5 V supply |
| Pin produk 9 | GND — Ground |
| Pin produk 10 | BGND — Bus grant (debug) |
| Pin produk 11 | BR — Bus request |
| Pin produk 12 | BG — Bus grant |
| Pin produk 13 | RMC — Read-modify-write cycle |
| Pin produk 14 | SIZ0 — Transfer size bit 0 |
| Pin produk 15 | SIZ1 — Transfer size bit 1 |
| Pin produk 16 | FC0 — Function code bit 0 |
| Pin produk 17 | FC1 — Function code bit 1 |
| Pin produk 18 | FC2 — Function code bit 2 |
| Pin produk 19 | A0 — Address bus bit 0 |
| Pin produk 20 | A1 — Address bus bit 1 |
| Pin produk 21 | A2 — Address bus bit 2 |
| Pin produk 22 | A3 — Address bus bit 3 |
| Pin produk 23 | A4 — Address bus bit 4 |
| Pin produk 24 | A5 — Address bus bit 5 |
| Pin produk 25 | A6 — Address bus bit 6 |
| Pin produk 26 | A7 — Address bus bit 7 |
| Pin produk 27 | A8 — Address bus bit 8 |
| Pin produk 28 | A9 — Address bus bit 9 |
| Pin produk 29 | A10 — Address bus bit 10 |
| Pin produk 30 | A11 — Address bus bit 11 |
| Pin produk 31 | A12 — Address bus bit 12 |
| Pin produk 32 | A13 — Address bus bit 13 |
| Pin produk 33 | A14 — Address bus bit 14 |
| Pin produk 34 | A15 — Address bus bit 15 |
| Pin produk 35 | A16 — Address bus bit 16 |
| Pin produk 36 | A17 — Address bus bit 17 |
| Pin produk 37 | A18 — Address bus bit 18 |
| Pin produk 38 | A19 — Address bus bit 19 |
| Pin produk 39 | A20 — Address bus bit 20 |
| Pin produk 40 | A21 — Address bus bit 21 |
| Pin produk 41 | A22 — Address bus bit 22 |
| Pin produk 42 | A23 — Address bus bit 23 |
| Pin produk 43 | A24 — Address bus bit 24 |
| Pin produk 44 | A25 — Address bus bit 25 |
| Pin produk 45 | A26 — Address bus bit 26 |
| Pin produk 46 | A27 — Address bus bit 27 |
| Pin produk 47 | A28 — Address bus bit 28 |
| Pin produk 48 | A29 — Address bus bit 29 |
| Pin produk 49 | A30 — Address bus bit 30 |
| Pin produk 50 | A31 — Address bus bit 31 |
| Pin produk 51 | D0 — Data bus bit 0 |
| Pin produk 52 | D1 — Data bus bit 1 |
| Pin produk 53 | D2 — Data bus bit 2 |
| Pin produk 54 | D3 — Data bus bit 3 |
| Pin produk 55 | D4 — Data bus bit 4 |
| Pin produk 56 | D5 — Data bus bit 5 |
| Pin produk 57 | D6 — Data bus bit 6 |
| Pin produk 58 | D7 — Data bus bit 7 |
| Pin produk 59 | D8 — Data bus bit 8 |
| Pin produk 60 | D9 — Data bus bit 9 |
| Pin produk 61 | D10 — Data bus bit 10 |
| Pin produk 62 | D11 — Data bus bit 11 |
| Pin produk 63 | D12 — Data bus bit 12 |
| Pin produk 64 | D13 — Data bus bit 13 |
| Pin produk 65 | D14 — Data bus bit 14 |
| Pin produk 66 | D15 — Data bus bit 15 |
| Pin produk 67 | CLK — System clock input (25 MHz) |
| Pin produk 68 | VCC — +5 V supply |
Aplikasi Umum
MC68882EI25AR cocok untuk 6 aplikasis: Amiga 3000/4000 FPU Upgrade, Atari TT/Falcon FPU Acceleration, Industrial 68k Control Retrofit, Vintage Computer Restoration, Educational / Emulator Development Platform, Legacy Aerospace / Defense Test Equipment.
Amiga 3000/4000 FPU Upgrade
The MC68882EI25AR at 25 MHz pairs directly with the Amiga 3000 and 4000's MC68030 host CPU through the 68k coprocessor interface, delivering IEEE 754 single/double/extended precision in hardware for ray-traced rendering, fractal generation, and audio DSP. At matched 25 MHz clock, the 68882 completes a double-precision multiply in roughly 5 cycles while the host runs concurrently, a substantial speed-up over software FPU emulation on a bare 68030. Designers must place the PLCC-68 socket within 50 mm of the host CPU to keep coprocessor-handshake timing within spec.
Direkomendasikan
Atari TT/Falcon FPU Acceleration
Atari TT030 and Falcon030 workstations used the MC68882EI25AR as a drop-in FPU companion to the 68030 host, accelerating CAD/CAM, desktop publishing, and DSP workloads on the 68k platform. The 25 MHz grade was the standard FPU option for the TT030 in PLCC-68 form factor. Installing the part into the dedicated coprocessor socket adds IEEE 754 hardware without firmware changes; the TOS operating system transparently dispatches F-line opcodes to the 68882 as soon as the host detects it during POST.
Direkomendasikan
Industrial 68k Control Retrofit
Long-lifecycle industrial controllers based on the MC68020 or MC68030 often retained the MC68882EI25AR for hardware floating-point servo-loop math, where integer-only control would have required excessive software overhead. The commercial 0C to +70C grade is suitable for enclosed control cabinets. Because the part is obsolete, retrofit boards typically source verified stock from franchised distributors such as Rochester Electronics to keep installed-base equipment operational for 10 to 20 additional years.
Direkomendasikan
Vintage Computer Restoration
The MC68882EI25AR is a frequent replacement part for restoring vintage 68k workstations, particularly Apple Macintosh II/Quadra logic boards via PDS-card-hosted sockets and early Sun 3 NPU upgrades. Because new-old stock and tested pulls command premium pricing, restoration communities typically match date codes and lot numbers when sourcing. The PLCC-68 J-lead package allows hobbyists to socket the part and avoid repeated soldering during diagnostics.
Direkomendasikan
Educational / Emulator Development Platform
Universities and open-source emulator projects (such as ARAnyM, Hatari, and Basilisk II) target the MC68882EI25AR because it represents the canonical 68k FPU to emulate for cycle-accurate behavior. The 25 MHz grade is the most commonly documented timing reference in published 68k FPU performance literature. Including a verified 68882 in a hardware-emulation test rig allows emulator authors to cross-check edge cases (denormals, NaN propagation, rounding modes) against real silicon behavior.
Direkomendasikan
Legacy Aerospace / Defense Test Equipment
Some 1990s-vintage aerospace ground-test racks retain 68k processors with the MC68882EI25AR for floating-point signal-processing math (radar return simulation, FFT preprocessing). These programs run on long support timelines (20+ years) and rely on the franchised aftermarket to sustain installed equipment. Procurement specifications require traceability to the original Motorola lot, certificate of conformance, and 100 percent pre-screening on a 68k development board before deployment.
Direkomendasikan
Ringkasan Produk Direkomendasikan
Data referensi engineering untuk MC68882EI25AR — pembandingan, panduan desain, dan informasi konformitas.
Panduan Pemilihan
Pembandingan dengan Alternatif
| Parameter Umum | Produk Ini | MC68882EI16A | MC68882EI20A | MC68882EI33A | MC68882EI40A |
|---|---|---|---|---|---|
| Package | 68-PLCC (J-Lead) | 68-PLCC (J-Lead) | 68-PLCC (J-Lead) | 68-PLCC (J-Lead) | 68-PLCC (J-Lead) |
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Operating Frequency | 25 MHz | 16 MHz | 20 MHz | 33 MHz | 40 MHz |
| Supply Voltage | 5 V (4.75 V to 5.25 V) | 5 V (4.75 V to 5.25 V) | 5 V (4.75 V to 5.25 V) | 5 V (4.75 V to 5.25 V) | 5 V (4.75 V to 5.25 V) |
| Temperature Grade | Commercial (0C to +70C) | Commercial (0C to +70C) | Commercial (0C to +70C) | Commercial (0C to +70C) | Commercial (0C to +70C) |
| Floating-Point Standard | IEEE 754 single/double/extended | IEEE 754 single/double/extended | IEEE 754 single/double/extended | IEEE 754 single/double/extended | IEEE 754 single/double/extended |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete |
| Host CPU Compatibility | MC68020 / MC68030 / MC68040 | MC68020 / MC68030 / MC68040 | MC68020 / MC68030 / MC68040 | MC68020 / MC68030 / MC68040 | MC68020 / MC68030 / MC68040 |
Diferensiator Kunci
- Balanced clock speed for MC68030 hosts (vsMC68882EI16A)
- Lower power consumption than 33/40 MHz grades (vsMC68882EI33A)
- Commercial temperature range only (vsMC68882RC25A)
Catatan Desain
Place the MC68882EI25AR within 50 mm of the host MC68030 on the motherboard and keep the coprocessor-handshake traces (DSACK0/1, AVEC, BG, BR, RMC) short and matched in length within 12 mm. The 68882 is sensitive to coprocessor-bus skew; long stubs or excessive capacitive loading cause intermittent FPU detection failures. Use a ground guard trace around the coprocessor bus to limit crosstalk from the host data bus. Decouple each VCC pin with 0.1 uF ceramic plus one shared 10 uF tantalum bulk capacitor.
Drive the CLK pin with a clock source that matches the host MC68030 clock frequency within +/- 100 ppm. Mismatched clocks break the coprocessor handshake protocol and cause the host to time out on F-line instructions. Use a low-jitter clock driver (jitter under 200 ps peak-peak) and place a 33 ohm series-termination resistor near the 68882 CLK pin if the trace exceeds 25 mm. Avoid routing the clock trace over split-plane regions or near switching power-supply nodes.
Do not pair the MC68882EI25AR with an MC68040 host CPU - the 68040 includes an integrated FPU and does not expose the coprocessor interface in a way that supports an external 68882. The most common build error is mounting the part in a PGA-68 socket (which expects the MC68882RC PGA variant) or vice versa. Always verify the suffix: 'EI' means PLCC-68 J-lead, 'RC' means ceramic PGA-68. Both share the same die but require different footprints.
Informasi Konformitas
Matte-tin terminal finish supports lead-free assembly. RoHS compliance reported by distributor channels based on terminal finish; lot-level declarations should be requested from the supplier. REACH, halogen-free, and conflict-minerals status not explicitly published for this obsolete part.
