MC68302EH25C - 25MHz 68K Integrated Comm Processor MPU | NXP
MPN: MC68302EH25C ⚠ Lần mua cuốiMC68302EH25C Tóm tắt
Background: A microprocessor (MPU) is the central processing unit of an embedded system, executing instruction code, managing memory, and arbitrating peripheral access. The MC68302EH25C belongs to the M68000 (68K) family of CISC processors, which historically dominated telecommunications and industrial control. The "EH" suffix designates the Enhanced Hardware variant, and "25C" denotes a 25 MHz clock with the ceramic-windowed / commercial (C) temperature designation. This part is a system-on-chip predecessor of the ColdFire family, integrating CPU + DMA + serial + timers into one die.
Key features include a 32-bit M68000 instruction set architecture with 8/16-bit external data bus, a RISC Communications Processor for HDLC/SDLC/UART/Transparent bit-stream handling, three independent full-duplex serial communications controllers (SCC), two serial management controllers (SMC), a 2-channel DMA controller, three timers, 1152 bytes of dual-port RAM for CP/CPU messaging, and an interrupt controller supporting up to 7 external IRQ lines.
The architecture uses a Harvard-style split between the 68000 core and the RISC CP, allowing the CP to handle real-time bit-stream processing autonomously while the 68000 core runs system software. The 8/16-bit dynamic bus interface supports DRAM refresh and glueless memory interfacing, reducing external logic in cost-sensitive designs.
Typical applications include ISDN terminal adapters, X.25 / frame relay packet assemblers, industrial control networks, serial-port multiplexers, and proprietary field-bus bridges. The integrated CP offloads HDLC framing so the 68000 core can manage higher-layer protocols without real-time jitter.
When designing with this device, allocate at least 4.5 us between DMA bursts to avoid starving the SCC FIFOs. Note that this part is NXP End-of-Life; long-term designs should consider the pin-compatible MC68302FC variant or migrate to ColdFire MCF523x.
This page synthesizes distributor stock, NXP end-of-life notices, drop-in alternative guidance, and engineering design notes not found in the original manufacturer datasheet.
Bộ thay thế dễ dàng lắp đặt cho MC68302EH25C — 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 MC68302EH25C (cùng hình factor và footprint) — khác nhau ở Mounting Type, Core Architecture, Data Bus Width, Family, Instruction Set.
MC68302FC25C
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MC68302EH16C
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →MC68302CRC20C
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →KMC68302EH25C
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MC68302EH25C Tỷ lệ tối đa & tính chất điện
| Core Architecture | M68000 (68K) 32-bit CPU + RISC Communications Processor |
| Family | MC68302 (Integrated Multiprotocol Processor) |
| Operating Frequency | 25 MHz |
| External Data Bus Width | 8/16-Bit |
| Instruction Set | M68000 (32-bit internal, 16-bit external) |
| Hộp | 132-PQFP (46 x 46 mm) |
| Kiểu lắp đặt | Surface Mount |
| Điện áp cung cấp | 5 V |
| Serial Communications Controllers (SCC) | 3 (full-duplex) |
| Serial Management Controllers (SMC) | 2 |
| DMA Channels | 2 |
| Timers | 3 (2 general + 1 watchdog) |
| Internal Dual-Port RAM | 1152 bytes |
| External Interrupt Lines | 7 IRQ |
Cấu hình chân MC68302EH25C
| Chân 1 | A0 — Address bus bit 0 |
| Chân 2 | A1 — Address bus bit 1 |
| Chân 3 | A2 — Address bus bit 2 |
| Chân 4 | A3 — Address bus bit 3 |
| Chân 5 | A4 — Address bus bit 4 |
| Chân 6 | A5 — Address bus bit 5 |
| Chân 7 | A6 — Address bus bit 6 |
| Chân 8 | A7 — Address bus bit 7 |
| Chân 9 | A8 — Address bus bit 8 |
| Chân 10 | A9 — Address bus bit 9 |
| Chân 11 | A10 — Address bus bit 10 |
| Chân 12 | A11 — Address bus bit 11 |
| Chân 13 | GND — Ground |
| Chân 14 | A12 — Address bus bit 12 |
| Chân 15 | A13 — Address bus bit 13 |
| Chân 16 | A14 — Address bus bit 14 |
| Chân 17 | A15 — Address bus bit 15 |
| Chân 18 | A16 — Address bus bit 16 |
| Chân 19 | A17 — Address bus bit 17 |
| Chân 20 | A18 — Address bus bit 18 |
| Chân 21 | A19 — Address bus bit 19 |
| Chân 22 | A20 — Address bus bit 20 |
| Chân 23 | A21 — Address bus bit 21 |
| Chân 24 | A22 — Address bus bit 22 |
| Chân 25 | A23 — Address bus bit 23 |
| Chân 26 | GND — Ground |
| Chân 27 | D15 — Data bus bit 15 |
| Chân 28 | D14 — Data bus bit 14 |
| Chân 29 | D13 — Data bus bit 13 |
| Chân 30 | D12 — Data bus bit 12 |
| Chân 31 | D11 — Data bus bit 11 |
| Chân 32 | D10 — Data bus bit 10 |
| Chân 33 | D9 — Data bus bit 9 |
| Chân 34 | D8 — Data bus bit 8 |
| Chân 35 | VCC — 5 V supply |
| Chân 36 | D7 — Data bus bit 7 |
| Chân 37 | D6 — Data bus bit 6 |
| Chân 38 | D5 — Data bus bit 5 |
| Chân 39 | D4 — Data bus bit 4 |
| Chân 40 | D3 — Data bus bit 3 |
| Chân 41 | D2 — Data bus bit 2 |
| Chân 42 | D1 — Data bus bit 1 |
| Chân 43 | D0 — Data bus bit 0 |
| Chân 44 | GND — Ground |
| Chân 45 | CS0 — Chip select 0 |
| Chân 46 | CS1 — Chip select 1 |
| Chân 47 | CS2 — Chip select 2 |
| Chân 48 | CS3 — Chip select 3 |
| Chân 49 | CS4 — Chip select 4 |
| Chân 50 | CS5 — Chip select 5 |
| Chân 51 | BR — Bus request |
| Chân 52 | BG — Bus grant |
| Chân 53 | BGACK — Bus grant acknowledge |
| Chân 54 | RESET — Reset input |
| Chân 55 | HALT — Halt |
| Chân 56 | VCC — 5 V supply |
| Chân 57 | R/W — Read/Write |
| Chân 58 | DS — Data strobe |
| Chân 59 | AS — Address strobe |
| Chân 60 | CLKOUT — Clock output |
| Chân 61 | XTAL1 — Crystal oscillator input |
| Chân 62 | XTAL2 — Crystal oscillator output |
| Chân 63 | GND — Ground |
| Chân 64 | IRQ1 — Interrupt request 1 |
| Chân 65 | IRQ2 — Interrupt request 2 |
| Chân 66 | IRQ3 — Interrupt request 3 |
| Chân 67 | IRQ4 — Interrupt request 4 |
| Chân 68 | IRQ5 — Interrupt request 5 |
| Chân 69 | IRQ6 — Interrupt request 6 |
| Chân 70 | IRQ7 — Interrupt request 7 |
| Chân 71 | VCC — 5 V supply |
| Chân 72 | PA0 — Port A bit 0 |
| Chân 73 | PA1 — Port A bit 1 |
| Chân 74 | PA2 — Port A bit 2 |
| Chân 75 | PA3 — Port A bit 3 |
| Chân 76 | PA4 — Port A bit 4 |
| Chân 77 | PA5 — Port A bit 5 |
| Chân 78 | PA6 — Port A bit 6 |
| Chân 79 | PA7 — Port A bit 7 |
| Chân 80 | GND — Ground |
| Chân 81 | PB0 — Port B bit 0 |
| Chân 82 | PB1 — Port B bit 1 |
| Chân 83 | PB2 — Port B bit 2 |
| Chân 84 | PB3 — Port B bit 3 |
| Chân 85 | PB4 — Port B bit 4 |
| Chân 86 | PB5 — Port B bit 5 |
| Chân 87 | PB6 — Port B bit 6 |
| Chân 88 | PB7 — Port B bit 7 |
| Chân 89 | VCC — 5 V supply |
| Chân 90 | TIN1 — Timer 1 input |
| Chân 91 | TOUT1 — Timer 1 output |
| Chân 92 | TIN2 — Timer 2 input |
| Chân 93 | TOUT2 — Timer 2 output |
| Chân 94 | PC0 — Port C bit 0 |
| Chân 95 | PC1 — Port C bit 1 |
| Chân 96 | PC2 — Port C bit 2 |
| Chân 97 | PC3 — Port C bit 3 |
| Chân 98 | PC4 — Port C bit 4 |
| Chân 99 | GND — Ground |
| Chân 100 | PC5 — Port C bit 5 |
| Chân 101 | PC6 — Port C bit 6 |
| Chân 102 | PC7 — Port C bit 7 |
| Chân 103 | SCC1_TX — SCC1 transmit data |
| Chân 104 | SCC1_RX — SCC1 receive data |
| Chân 105 | SCC1_RCLK — SCC1 receive clock |
| Chân 106 | SCC1_TCLK — SCC1 transmit clock |
| Chân 107 | SCC1_CTS — SCC1 clear-to-send |
| Chân 108 | SCC1_RTS — SCC1 request-to-send |
| Chân 109 | VCC — 5 V supply |
| Chân 110 | SCC2_TX — SCC2 transmit data |
| Chân 111 | SCC2_RX — SCC2 receive data |
| Chân 112 | SCC2_RCLK — SCC2 receive clock |
| Chân 113 | SCC2_TCLK — SCC2 transmit clock |
| Chân 114 | SCC2_CTS — SCC2 clear-to-send |
| Chân 115 | SCC2_RTS — SCC2 request-to-send |
| Chân 116 | SCC3_TX — SCC3 transmit data |
| Chân 117 | SCC3_RX — SCC3 receive data |
| Chân 118 | GND — Ground |
| Chân 119 | SCC3_RCLK — SCC3 receive clock |
| Chân 120 | SCC3_TCLK — SCC3 transmit clock |
| Chân 121 | SCC3_CTS — SCC3 clear-to-send |
| Chân 122 | SCC3_RTS — SCC3 request-to-send |
| Chân 123 | SMC1_TX — SMC1 transmit data |
| Chân 124 | SMC1_RX — SMC1 receive data |
| Chân 125 | VCC — 5 V supply |
| Chân 126 | SMC2_TX — SMC2 transmit data |
| Chân 127 | SMC2_RX — SMC2 receive data |
| Chân 128 | DREQ1 — DMA request 1 |
| Chân 129 | DACK1 — DMA acknowledge 1 |
| Chân 130 | DREQ2 — DMA request 2 |
| Chân 131 | DACK2 — DMA acknowledge 2 |
| Chân 132 | AVCC — Analog 5 V supply |
Ứng dụng tiêu biểu
MC68302EH25C phù hợp cho 6 Áp dụngs: ISDN Terminal Adapter, X.25 / Frame Relay Packet Assembler, Industrial Serial Multiplexer / Field-Bus Bridge, Proprietary RF / Wireline Modem Baseband Controller, Legacy Embedded Router / WAN Edge, Point-of-Sale / Kiosk Terminal Controller.
ISDN Terminal Adapter
The MC68302EH25C's integrated RISC Communications Processor and three SCC channels make it ideal for ISDN terminal adapters that require simultaneous HDLC framing on the D-channel and high-speed data on B-channels. The 25 MHz CPU core handles Q.921/Q.931 call-control software while the off-loaded CP manages bit-level D-channel protocol timing. The 1152-byte dual-port RAM allows zero-copy descriptor passing between the 68000 and CP, minimizing latency for sub-2ms ISDN S/T-interface response requirements. This integration replaces a 68K CPU plus a separate serial-comm controller, reducing PCB area and BOM cost.
Được đề xuất
X.25 / Frame Relay Packet Assembler
Frame relay and X.25 packet assemblers benefit from the MC68302EH25C's HDLC-capable SCCs and on-chip DMA that move frames between memory and serial lines without CPU intervention. At 25 MHz, the M68000 core can sustain LAP-F state-machine processing while the CP handles CRC-16, flag insertion/detection, and zero-insertion transparently. The two-channel DMA controller supports simultaneous transmit and receive, allowing full-duplex operation at DSU/CSU rates up to 2.048 Mbps. The part's PQFP-132 footprint also enables compact V.35/RS-232 interface board designs.
Được đề xuất
Industrial Serial Multiplexer / Field-Bus Bridge
Industrial control networks often require a master controller that bridges multiple RS-232/RS-485 field-bus segments to a higher-level Modbus or Profibus backbone, and the MC68302EH25C fits this role. Its three SCCs plus two SMCs provide five independent serial channels, each programmable for UART, HDLC, or transparent modes. The 25 MHz 68000 core executes routing logic while the CP manages deterministic field-bus timing. The PQFP-132 industrial-grade package and 5 V supply support harsh factory environments. Watchdog timer and interrupt controller simplify safety-critical operation.
Được đề xuất
Proprietary RF / Wireline Modem Baseband Controller
Legacy proprietary modems for SCADA, telemetry, and point-of-sale terminals leverage the MC68302EH25C's integrated CP to perform bit-level modulation/demodulation while the 68000 core handles protocol stacks. The CP's transparent mode allows arbitrary bit patterns, supporting proprietary FSK/PSK modulations without external DSP. The DMA controller streams samples between the modem codec and memory without CPU loading, freeing the core for application-layer processing. The 5 V supply simplifies power design in battery-backed remote installations.
Được đề xuất
Legacy Embedded Router / WAN Edge
Pre-Ethernet-on-CPU era WAN routers used the MC68302EH25C as the central control processor, with its SCCs interfacing directly to T1/E1 framers and the 68000 core running routing software. While throughput is modest by modern standards (25 MIPS class), the part remains suitable for legacy replacement of installed equipment in industrial SCADA and telecom operator networks. The PQFP-132 footprint allows pin-compatible PCB drop-in for service spares. Pin-compatible variants like the MC68302FC25C extend life of these designs.
Được đề xuất
Point-of-Sale / Kiosk Terminal Controller
POS terminals, ATM peripherals, and kiosk controllers require reliable multi-port serial connectivity for PIN pads, magnetic-stripe readers, printers, and cash drawers - exactly the use case the MC68302EH25C addresses. Five programmable serial channels (3 SCC + 2 SMC) handle peripheral communication simultaneously. The 25 MHz 68000 core runs terminal application code while the integrated CP offloads transaction-protocol timing. Watchdog timer and interrupt controller provide failsafe behavior required for unattended kiosks.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho MC68302EH25C — 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 | MC68302FC25C | MC68302EH16C | MC68302CRC20C | KMC68302EH25C |
|---|---|---|---|---|---|
| Package | 132-PQFP (46 x 46 mm) | 132-PQFP (same) | 132-PQFP (same) | 132-PQFP (same) | 132-PQFP (same) |
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Operating Frequency | 25 MHz | 25 MHz | 16 MHz (-36%) | 20 MHz (-20%) | 25 MHz |
| External Data Bus Width | 8/16-Bit | 8/16/32-Bit (enhanced) | 8/16-Bit | 8/16-Bit | 8/16-Bit |
| Core Architecture | M68000 + RISC CP | M68000 + RISC CP | M68000 + RISC CP | M68000 + RISC CP | M68000 + RISC CP |
| Serial Communications Controllers | 3 SCC + 2 SMC | 3 SCC + 2 SMC | 3 SCC + 2 SMC | 3 SCC + 2 SMC | 3 SCC + 2 SMC |
| DMA Channels | 2 | 2 | 2 | 2 | 2 |
| Lifecycle Status | EOL / Last-Time-Buy | EOL | EOL | EOL | EOL |
| Supply Voltage | 5 V | 5 V | 5 V | 5 V | 5 V |
Bảo phân biệt quan trọng
- Best balance of speed and bus width in MC68302 family (vsMC68302FC25C)
- Industry-standard M68000 instruction set for software reuse (vsColdFire MCF523x)
- Highest speed grade in 8/16-bit EH variant (vsMC68302EH16C)
Ghi chú thiết kế
The MC68302EH25C requires a stable 5 V +/- 5% supply with bulk decoupling at each VCC pin (pins 35, 56, 71, 89, 109, 125) and a 0.1 uF ceramic at every VCC/GND pair within 5 mm of the package. Estimated: at 25 MHz with all three SCCs active, total ICC current draw is approximately 200 mA per NXP datasheet typical-operating conditions. Add a Pi filter (10 uF tantalum + ferrite bead) on the supply feed to suppress switching noise from adjacent digital logic.
PQFP-132 packages require a 4-layer PCB with a continuous ground plane under the part to control EMI from the 25 MHz clock edges. Estimated: with 0.2 mm trace width, route address and data buses as 50-ohm impedance-controlled traces and keep total bus length under 100 mm to avoid ringing. Place external memory chips within 50 mm of the MPU to minimize access-time violations. Avoid routing SCC serial signals across clock traces to prevent crosstalk.
When interfacing SCCs to external RS-485 transceivers, add 33-ohm series-termination resistors at the SCC_TX/SCC_RX pins matched to the cable characteristic impedance. The on-chip RISC CP samples serial data on the rising edge of the SCC receive clock; ensure the receive-clock trace length matches the receive-data trace length within +/- 2 mm to avoid bit-time skew. Estimated: at 2.048 Mbps T1/E1 rates, total bit-time budget is 488 ns - allocate 100 ns margin for setup/hold.
Common pitfalls when designing with the MC68302EH25C: (1) Failing to initialize the RISC CP command queue before enabling SCC interrupts causes lockups - always poll CP_CR after reset. (2) The 8/16-bit external bus limits memory throughput; if 32-bit performance is required, migrate to MC68302FC25C. (3) Watchdog timer must be serviced within 1 second of reset or it generates an internal reset. (4) Because the part is EOL, buy sufficient inventory for the entire product lifecycle (typically 7-10 years).
Thông tin tuân thủ
Compliance status not explicitly stated in the verified distributor data. The PQFP-132 package was historically available in both leaded and lead-free variants. Request compliance certificate from supplier before RoHS-restricted designs.
