MC68302EH25C - 25MHz 68K Integrated Comm Processor MPU | NXP
MPN: MC68302EH25C ⚠ רכישה אחרונהMC68302EH25C סקירה
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.
חלופות תחליף ישיר עבור MC68302EH25C — אותו מארז, תואם פין-לפין. חלקים במארז שונה הדורשים עיבוד מחדש של ה-PCB אינם נכללים.
וריאנטים בסדרה זו
דגמים מאותה סדרה התואמים Drop-in עם MC68302EH25C (אותו גורם צורה וטביעת רגל) — שונים ב Mounting Type, Core Architecture, Data Bus Width, Family, Instruction Set.
MC68302FC25C
✅ Drop-In📋 חלופה להתייחסות (לא בקטלוג)
MC68302EH16C
✅ Drop-Inצור קשר לקבלת מחיר
הצג גיליון נתונים ←MC68302CRC20C
✅ Drop-Inצור קשר לקבלת מחיר
הצג גיליון נתונים ←KMC68302EH25C
✅ Drop-In📋 חלופה להתייחסות (לא בקטלוג)
MC68302EH25C דירוגים מרביים ומאפיינים חשמליים
| 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) |
| מארז | 132-PQFP (46 x 46 mm) |
| סוג הרכבה | Surface Mount |
| מתח אספקה | 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 |
תצורת פינים של MC68302EH25C
| פין 1 | A0 — Address bus bit 0 |
| פין 2 | A1 — Address bus bit 1 |
| פין 3 | A2 — Address bus bit 2 |
| פין 4 | A3 — Address bus bit 3 |
| פין 5 | A4 — Address bus bit 4 |
| פין 6 | A5 — Address bus bit 5 |
| פין 7 | A6 — Address bus bit 6 |
| פין 8 | A7 — Address bus bit 7 |
| פין 9 | A8 — Address bus bit 8 |
| פין 10 | A9 — Address bus bit 9 |
| פין 11 | A10 — Address bus bit 10 |
| פין 12 | A11 — Address bus bit 11 |
| פין 13 | GND — Ground |
| פין 14 | A12 — Address bus bit 12 |
| פין 15 | A13 — Address bus bit 13 |
| פין 16 | A14 — Address bus bit 14 |
| פין 17 | A15 — Address bus bit 15 |
| פין 18 | A16 — Address bus bit 16 |
| פין 19 | A17 — Address bus bit 17 |
| פין 20 | A18 — Address bus bit 18 |
| פין 21 | A19 — Address bus bit 19 |
| פין 22 | A20 — Address bus bit 20 |
| פין 23 | A21 — Address bus bit 21 |
| פין 24 | A22 — Address bus bit 22 |
| פין 25 | A23 — Address bus bit 23 |
| פין 26 | GND — Ground |
| פין 27 | D15 — Data bus bit 15 |
| פין 28 | D14 — Data bus bit 14 |
| פין 29 | D13 — Data bus bit 13 |
| פין 30 | D12 — Data bus bit 12 |
| פין 31 | D11 — Data bus bit 11 |
| פין 32 | D10 — Data bus bit 10 |
| פין 33 | D9 — Data bus bit 9 |
| פין 34 | D8 — Data bus bit 8 |
| פין 35 | VCC — 5 V supply |
| פין 36 | D7 — Data bus bit 7 |
| פין 37 | D6 — Data bus bit 6 |
| פין 38 | D5 — Data bus bit 5 |
| פין 39 | D4 — Data bus bit 4 |
| פין 40 | D3 — Data bus bit 3 |
| פין 41 | D2 — Data bus bit 2 |
| פין 42 | D1 — Data bus bit 1 |
| פין 43 | D0 — Data bus bit 0 |
| פין 44 | GND — Ground |
| פין 45 | CS0 — Chip select 0 |
| פין 46 | CS1 — Chip select 1 |
| פין 47 | CS2 — Chip select 2 |
| פין 48 | CS3 — Chip select 3 |
| פין 49 | CS4 — Chip select 4 |
| פין 50 | CS5 — Chip select 5 |
| פין 51 | BR — Bus request |
| פין 52 | BG — Bus grant |
| פין 53 | BGACK — Bus grant acknowledge |
| פין 54 | RESET — Reset input |
| פין 55 | HALT — Halt |
| פין 56 | VCC — 5 V supply |
| פין 57 | R/W — Read/Write |
| פין 58 | DS — Data strobe |
| פין 59 | AS — Address strobe |
| פין 60 | CLKOUT — Clock output |
| פין 61 | XTAL1 — Crystal oscillator input |
| פין 62 | XTAL2 — Crystal oscillator output |
| פין 63 | GND — Ground |
| פין 64 | IRQ1 — Interrupt request 1 |
| פין 65 | IRQ2 — Interrupt request 2 |
| פין 66 | IRQ3 — Interrupt request 3 |
| פין 67 | IRQ4 — Interrupt request 4 |
| פין 68 | IRQ5 — Interrupt request 5 |
| פין 69 | IRQ6 — Interrupt request 6 |
| פין 70 | IRQ7 — Interrupt request 7 |
| פין 71 | VCC — 5 V supply |
| פין 72 | PA0 — Port A bit 0 |
| פין 73 | PA1 — Port A bit 1 |
| פין 74 | PA2 — Port A bit 2 |
| פין 75 | PA3 — Port A bit 3 |
| פין 76 | PA4 — Port A bit 4 |
| פין 77 | PA5 — Port A bit 5 |
| פין 78 | PA6 — Port A bit 6 |
| פין 79 | PA7 — Port A bit 7 |
| פין 80 | GND — Ground |
| פין 81 | PB0 — Port B bit 0 |
| פין 82 | PB1 — Port B bit 1 |
| פין 83 | PB2 — Port B bit 2 |
| פין 84 | PB3 — Port B bit 3 |
| פין 85 | PB4 — Port B bit 4 |
| פין 86 | PB5 — Port B bit 5 |
| פין 87 | PB6 — Port B bit 6 |
| פין 88 | PB7 — Port B bit 7 |
| פין 89 | VCC — 5 V supply |
| פין 90 | TIN1 — Timer 1 input |
| פין 91 | TOUT1 — Timer 1 output |
| פין 92 | TIN2 — Timer 2 input |
| פין 93 | TOUT2 — Timer 2 output |
| פין 94 | PC0 — Port C bit 0 |
| פין 95 | PC1 — Port C bit 1 |
| פין 96 | PC2 — Port C bit 2 |
| פין 97 | PC3 — Port C bit 3 |
| פין 98 | PC4 — Port C bit 4 |
| פין 99 | GND — Ground |
| פין 100 | PC5 — Port C bit 5 |
| פין 101 | PC6 — Port C bit 6 |
| פין 102 | PC7 — Port C bit 7 |
| פין 103 | SCC1_TX — SCC1 transmit data |
| פין 104 | SCC1_RX — SCC1 receive data |
| פין 105 | SCC1_RCLK — SCC1 receive clock |
| פין 106 | SCC1_TCLK — SCC1 transmit clock |
| פין 107 | SCC1_CTS — SCC1 clear-to-send |
| פין 108 | SCC1_RTS — SCC1 request-to-send |
| פין 109 | VCC — 5 V supply |
| פין 110 | SCC2_TX — SCC2 transmit data |
| פין 111 | SCC2_RX — SCC2 receive data |
| פין 112 | SCC2_RCLK — SCC2 receive clock |
| פין 113 | SCC2_TCLK — SCC2 transmit clock |
| פין 114 | SCC2_CTS — SCC2 clear-to-send |
| פין 115 | SCC2_RTS — SCC2 request-to-send |
| פין 116 | SCC3_TX — SCC3 transmit data |
| פין 117 | SCC3_RX — SCC3 receive data |
| פין 118 | GND — Ground |
| פין 119 | SCC3_RCLK — SCC3 receive clock |
| פין 120 | SCC3_TCLK — SCC3 transmit clock |
| פין 121 | SCC3_CTS — SCC3 clear-to-send |
| פין 122 | SCC3_RTS — SCC3 request-to-send |
| פין 123 | SMC1_TX — SMC1 transmit data |
| פין 124 | SMC1_RX — SMC1 receive data |
| פין 125 | VCC — 5 V supply |
| פין 126 | SMC2_TX — SMC2 transmit data |
| פין 127 | SMC2_RX — SMC2 receive data |
| פין 128 | DREQ1 — DMA request 1 |
| פין 129 | DACK1 — DMA acknowledge 1 |
| פין 130 | DREQ2 — DMA request 2 |
| פין 131 | DACK2 — DMA acknowledge 2 |
| פין 132 | AVCC — Analog 5 V supply |
יישומים טיפוסיים
MC68302EH25C מתאים עבור 6 יישוםs: 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.
מומלץ
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.
מומלץ
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.
מומלץ
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.
מומלץ
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.
מומלץ
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.
מומלץ
סיכום מוצרים מומלצים
נתוני עזר הנדסיים עבור MC68302EH25C — השוואה, הנחיות תכנון ומידע על תאימות.
מדריך בחירה
השוואה עם חלופות
| פרמטר | מוצר זה | 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 |
מבדילים עיקריים
- Best balance of speed and bus width in MC68302 family (לעומתMC68302FC25C)
- Industry-standard M68000 instruction set for software reuse (לעומתColdFire MCF523x)
- Highest speed grade in 8/16-bit EH variant (לעומתMC68302EH16C)
הערות תכנון
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).
מידע על תאימות
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.
