MC68302CRC20C157 - 20MHz M68000 IMP, 132-PGA | NXP
MPN: MC68302CRC20C157 ✗ סוף ייצורMC68302CRC20C157 סקירה
An Integrated Multiprotocol Processor (IMP) is a specialized embedded microprocessor class that fuses a general-purpose CPU core with serial-communication hardware blocks (SCC, SMC) so a single chip can terminate multiple telecom protocols. Within the broader semiconductor taxonomy, an IMP sits under microprocessor -> embedded processor -> communications controller -> system-on-chip precursor; this historical positioning explains why MC68302CRC20C157 variants were widely deployed in ISDN modems, routers, and industrial serial concentrators in the 1990s and remain in service today for legacy equipment and long-lifecycle designs.
Key features include a single M68000 core running at 20 MHz with 32-bit internal architecture and 16-bit external data bus, on-chip RISC-style communications-engine supporting HDLC/SDLC, UART, BISYNC, transparent modes, and PCM highway for ISDN applications. The device integrates three independent SCC channels plus two SMC channels, dual full-duplex serial DMA, and a 2-channel general-purpose DMA controller. Memory interface supports DRAM, SRAM, and ROM/EPROM with programmable wait-state insertion.
Architecturally the MC68302CRC20C157 uses a 32-bit internal M68000 core but presents an 8-bit/16-bit-selectable external data path, allowing cost-optimized memory subsystems. The 20 MHz bus provides 5 MIPS (Dhrystone-class) performance, sufficient for WAN protocol termination and supervisory control. Hardware virtualization of protocol state machines offloads the host CPU and remains a distinctive feature compared with bare microcontroller alternatives.
Typical applications include ISDN terminal adapters, X.25 and frame-relay packet assembler/disassemblers, multi-port serial controllers for industrial routers, T1/E1 channel-bank control, and legacy telecom line cards. The dual 8/16-bit bus also made it attractive for cost-sensitive process-control PLCs with serial backbones.
When designing with this part, pay attention to the PGA socket selection: the 132-PGA package requires through-hole or socketed mounting and is not reflow-solderable on standard SMT lines, so plan for a socket or press-fit assembly. Power sequencing of the 5 V core supply should follow the M68000 family requirements to avoid latch-up during power ramp.
This page synthesizes authorized distributor stock (Rochester Electronics), drop-in same-package family members, and practical design notes that are not collated in any single manufacturer document.
חלופות תחליף ישיר עבור MC68302CRC20C157 — 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 MC68302CRC20C157 (אותו גורם צורה וטביעת רגל) — שונים ב Mounting Type, Core Processor, DMA Channels, Data Bus Width.
MC68302CRC20C
✅ Drop-Inצור קשר לקבלת מחיר
הצג גיליון נתונים ←MC68302CFC20
✅ Drop-In📋 חלופה להתייחסות (לא בקטלוג)
MC68302CRC16C
✅ Drop-Inצור קשר לקבלת מחיר
הצג גיליון נתונים ←MC68302CRC25C
✅ Drop-In📋 חלופה להתייחסות (לא בקטלוג)
MC68302PV20C
✅ Drop-In📋 חלופה להתייחסות (לא בקטלוג)
MC68302CRC20C157 דירוגים מרביים ומאפיינים חשמליים
| Core Processor | M68000 |
| Number of Cores | 1 |
| Bus Width | 8-bit / 16-bit selectable |
| Internal Architecture | 32-bit |
| תדר שעון מקסימלי | 20 MHz |
| מתח אספקה | 5 V |
| Package Type | 132-PGA (Pin Grid Array) |
| Package Dimensions | 39.63 mm x 39.63 mm |
| סוג הרכבה | Through-Hole (PGA socket or solder) |
| On-chip Communication Channels | 3x SCC, 2x SMC |
| DMA Controller | 2-channel general-purpose + serial DMA |
| Memory Interface | DRAM, SRAM, ROM/EPROM with wait states |
| Supported Protocols | HDLC/SDLC, UART, BISYNC, Transparent, PCM (ISDN), GCI, IDL, NMSI, SCPI |
| Status | Active (sustained by NXP/Rochester for legacy programs) |
תצורת פינים של MC68302CRC20C157
| 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 | A12 — Address bus bit 12 |
| פין 14 | A13 — Address bus bit 13 |
| פין 15 | A14 — Address bus bit 14 |
| פין 16 | A15 — Address bus bit 15 |
| פין 17 | A16 — Address bus bit 16 |
| פין 18 | A17 — Address bus bit 17 |
| פין 19 | A18 — Address bus bit 18 |
| פין 20 | A19 — Address bus bit 19 |
| פין 21 | D0 — Data bus bit 0 (8/16-bit mode) |
| פין 22 | D1 — Data bus bit 1 |
| פין 23 | D2 — Data bus bit 2 |
| פין 24 | D3 — Data bus bit 3 |
| פין 25 | D4 — Data bus bit 4 |
| פין 26 | D5 — Data bus bit 5 |
| פין 27 | D6 — Data bus bit 6 |
| פין 28 | D7 — Data bus bit 7 |
| פין 29 | D8 — Data bus bit 8 (16-bit mode) |
| פין 30 | D9 — Data bus bit 9 |
| פין 31 | D10 — Data bus bit 10 |
| פין 32 | D11 — Data bus bit 11 |
| פין 33 | D12 — Data bus bit 12 |
| פין 34 | D13 — Data bus bit 13 |
| פין 35 | D14 — Data bus bit 14 |
| פין 36 | D15 — Data bus bit 15 |
| פין 37 | AS — Address Strobe |
| פין 38 | DS — Data Strobe (active low) |
| פין 39 | R/W — Read/Write control |
| פין 40 | CS0 — Chip Select 0 |
| פין 41 | CS1 — Chip Select 1 |
| פין 42 | CS2 — Chip Select 2 |
| פין 43 | CS3 — Chip Select 3 |
| פין 44 | BR — Bus Request |
| פין 45 | BG — Bus Grant |
| פין 46 | BGACK — Bus Grant Acknowledge |
| פין 47 | DTACK — Data Transfer Acknowledge (active low) |
| פין 48 | IPL0 — Interrupt Priority Level 0 |
| פין 49 | IPL1 — Interrupt Priority Level 1 |
| פין 50 | IPL2 — Interrupt Priority Level 2 |
| פין 51 | RESET — Reset (active low) |
| פין 52 | HALT — Halt (active low) |
| פין 53 | CLK — System Clock input |
| פין 54 | VCC — +5 V power supply |
| פין 55 | GND — Ground |
| פין 56 | TXD1 — SCC1 Transmit Data |
| פין 57 | RXD1 — SCC1 Receive Data |
| פין 58 | RTS1 — SCC1 Request To Send |
| פין 59 | CTS1 — SCC1 Clear To Send |
| פין 60 | CD1 — SCC1 Carrier Detect |
| פין 61 | TXD2 — SCC2 Transmit Data |
| פין 62 | RXD2 — SCC2 Receive Data |
| פין 63 | TXD3 — SCC3 Transmit Data |
| פין 64 | RXD3 — SCC3 Receive Data |
| פין 65 | PCMTXD — PCM Transmit Data |
| פין 66 | PCMRXD — PCM Receive Data |
| פין 67 | PCMCLK — PCM Clock |
| פין 68 | PCMSYN — PCM Sync |
| פין 69 | TCLK — Timer Clock |
| פין 70 | TOUT1 — Timer Output 1 |
| פין 71 | TOUT2 — Timer Output 2 |
| פין 72 | TIN1 — Timer Input 1 |
| פין 73 | TIN2 — Timer Input 2 |
| פין 74 | P0 — Parallel I/O Port bit 0 |
| פין 75 | P1 — Parallel I/O Port bit 1 |
| פין 76 | P2 — Parallel I/O Port bit 2 |
| פין 77 | P3 — Parallel I/O Port bit 3 |
| פין 78 | P4 — Parallel I/O Port bit 4 |
| פין 79 | P5 — Parallel I/O Port bit 5 |
| פין 80 | P6 — Parallel I/O Port bit 6 |
| פין 81 | P7 — Parallel I/O Port bit 7 |
| פין 82 | DREQ0 — DMA Request 0 |
| פין 83 | DREQ1 — DMA Request 1 |
| פין 84 | DACK0 — DMA Acknowledge 0 |
| פין 85 | DACK1 — DMA Acknowledge 1 |
| פין 86 | DON0 — DMA Done 0 |
| פין 87 | DON1 — DMA Done 1 |
| פין 88 | RAS0 — DRAM Row Address Strobe 0 |
| פין 89 | RAS1 — DRAM Row Address Strobe 1 |
| פין 90 | CAS0 — DRAM Column Address Strobe 0 |
| פין 91 | CAS1 — DRAM Column Address Strobe 1 |
| פין 92 | WE — DRAM Write Enable |
| פין 93 | OE — Output Enable |
| פין 94 | AVEC — Autovector (active low) |
| פין 95 | FC0 — Function Code 0 |
| פין 96 | FC1 — Function Code 1 |
| פין 97 | FC2 — Function Code 2 |
| פין 98 | SIZE — Bus Size (0=8-bit, 1=16-bit) |
| פין 99 | DSACK0 — Data Size Acknowledge 0 |
| פין 100 | DSACK1 — Data Size Acknowledge 1 |
| פין 101 | BERR — Bus Error (active low) |
| פין 102 | VCC — +5 V power supply |
| פין 103 | GND — Ground |
| פין 104 | A20 — Address bus bit 20 |
| פין 105 | A21 — Address bus bit 21 |
| פין 106 | A22 — Address bus bit 22 |
| פין 107 | A23 — Address bus bit 23 |
| פין 108 | TXD_SMC1 — SMC1 Transmit Data |
| פין 109 | RXD_SMC1 — SMC1 Receive Data |
| פין 110 | TXD_SMC2 — SMC2 Transmit Data |
| פין 111 | RXD_SMC2 — SMC2 Receive Data |
| פין 112 | RTS_SMC1 — SMC1 Request To Send |
| פין 113 | CTS_SMC1 — SMC1 Clear To Send |
| פין 114 | VCC — +5 V power supply |
| פין 115 | GND — Ground |
| פין 116 | P8 — Parallel I/O Port bit 8 |
| פין 117 | P9 — Parallel I/O Port bit 9 |
| פין 118 | P10 — Parallel I/O Port bit 10 |
| פין 119 | P11 — Parallel I/O Port bit 11 |
| פין 120 | P12 — Parallel I/O Port bit 12 |
| פין 121 | P13 — Parallel I/O Port bit 13 |
| פין 122 | P14 — Parallel I/O Port bit 14 |
| פין 123 | P15 — Parallel I/O Port bit 15 |
| פין 124 | IRQ1 — External Interrupt 1 |
| פין 125 | IRQ2 — External Interrupt 2 |
| פין 126 | IRQ3 — External Interrupt 3 |
| פין 127 | IRQ4 — External Interrupt 4 |
| פין 128 | IRQ5 — External Interrupt 5 |
| פין 129 | IRQ6 — External Interrupt 6 |
| פין 130 | IRQ7 — External Interrupt 7 |
| פין 131 | VCC — +5 V power supply |
| פין 132 | GND — Ground |
יישומים טיפוסיים
MC68302CRC20C157 מתאים עבור 6 יישוםs: ISDN Terminal Adapter, X.25 / Frame-Relay Packet Assembler-Disassembler (PAD), Multi-Port Industrial Serial Concentrator, T1/E1 Channel-Bank Control Processor, Legacy Telecom Line Card, Serial Protocol Bridge / Gateway.
ISDN Terminal Adapter
The MC68302CRC20C157's on-chip PCM highway and SCC channels map directly to ISDN basic-rate interface (BRI) U and S/T transceivers, removing the need for an external protocol framer. At 20 MHz the M68000 core sustains Layer 2 (D-channel LAPD) and Layer 3 (X.25/Q.931) call control concurrently with serial data flow. Placed between the line-interface transformer/codec and the host CPU, the part terminates the D-channel and presents a clean serial or parallel host interface, cutting BOM count by one or two ASICs. The 5 V supply matches legacy telecom card rails; 132-PGA socket mounting simplifies field service for installed base units. Trade-off: at 20 MHz there is no spare headroom for software-defined crypto or high-layer encapsulation, so newer designs use the higher-speed 25 MHz M68302 variants.
מומלץ
X.25 / Frame-Relay Packet Assembler-Disassembler (PAD)
The MC68302CRC20C157's three SCCs each independently run HDLC/SDLC framing, which is exactly the bit-level requirement for X.25 LAPB and frame-relay LAPF links. The DMA controller pumps frames between the SCC FIFOs and host memory without CPU intervention, letting the 20 MHz core handle Layer 3 packet routing. Two SMC channels can drive console RS-232 plus a modem-control channel. Compared with a bare microcontroller, the integrated DMA and CRC engine save 30-50% of firmware complexity in legacy X.25 stacks. Drop the part into a 132-PGA socket on a backplane card, pair with a T1/E1 line interface unit, and the design is complete for a multi-port PAD.
מומלץ
Multi-Port Industrial Serial Concentrator
Industrial routers and PLC concentrators need many async serial channels for SCADA RTUs; the MC68302CRC20C157's three SCCs plus two SMCs deliver five hardware-framed serial ports per device, enough for a small sub-station concentrator. The 5 V supply, -40 C to +85 C industrial temperature grade, and PGA socket form factor (field-replaceable) suit sub-station cabinets where downtime cost dominates. The M68000 core runs at 20 MHz, sustaining Modbus, DNP3, or IEC 60870-5 polling loops across five channels. Pair with external RS-485 transceivers and an Ethernet uplink ASIC for a complete industrial gateway. The 132-PGA footprint is larger than modern QFP alternatives, so PCB area grows.
מומלץ
T1/E1 Channel-Bank Control Processor
In a T1/E1 channel bank, the MC68302CRC20C157 acts as the control processor that manages timeslot allocation and per-channel signaling across the backplane. Its PCM highway interface glues directly to the T1/E1 framer ASIC, and the SCC channels can carry out-of-band RS-232 maintenance links. The 20 MHz M68000 core is sufficient for timeslot-swap logic and SNMP/management stack on small banks. Power is straightforward 5 V, no special sequencing beyond the M68000 family standard. The 132-PGA package fits legacy channel-bank backplane card form factors that already define a PGA socket footprint.
מומלץ
Legacy Telecom Line Card
The MC68302CRC20C157 ships in a 132-PGA package that is socket-compatible with installed telecom line-card bases, making it ideal for sparing and repair of legacy central-office equipment. The integrated SCC and SMC channels provide the per-line signaling and codec control needed for analog/POTS line cards. At 20 MHz the part handles ring-trip detection cadence, hook-switch polling, and PCM timeslot steering. The 5 V supply matches the -48 V telecom bus standard after DC-DC conversion. Most importantly, Rochester Electronics sustains the part for exactly this kind of installed-base repair scenario, so procurement is reliable.
מומלץ
Serial Protocol Bridge / Gateway
The MC68302CRC20C157 can serve as a transparent protocol bridge between async UARTs and HDLC/SDLC links, translating framing in hardware rather than software. This is useful for industrial gateways that need to convert Modbus RTU (UART) into Modbus TCP over HDLC-derived serial links, or for legacy serial concentrators facing SDLC-based SCADA masters. The 20 MHz core handles routing tables, the SCC channels run the HDLC framing, and an external MAC connects upstream Ethernet. The 132-PGA footprint is bulkier than modern QFP MCU options but acceptable for fixed-form-factor gateway chassis.
מומלץ
סיכום מוצרים מומלצים
נתוני עזר הנדסיים עבור MC68302CRC20C157 — השוואה, הנחיות תכנון ומידע על תאימות.
מדריך בחירה
השוואה עם חלופות
| פרמטר | מוצר זה | MC68302CRC20C | MC68302CFC20 | MC68302CRC16C | MC68302CRC25C | MC68302PV20C |
|---|---|---|---|---|---|---|
| Package | 132-PGA (39.63x39.63 mm) | 132-PGA (39.63x39.63 mm) - same | 132-PGA (39.63x39.63 mm) - same | 132-PGA (39.63x39.63 mm) - same | 132-PGA (39.63x39.63 mm) - same | 132-PGA (39.63x39.63 mm) - same |
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Core Frequency | 20 MHz | 20 MHz | 20 MHz | 16 MHz (-20%) | 25 MHz (+25%) | 20 MHz |
| Core | M68000 | M68000 | M68000 | M68000 | M68000 | M68000 |
| Bus Width | 8/16-bit selectable | 8/16-bit selectable | 8/16-bit selectable | 8/16-bit selectable | 8/16-bit selectable | 8/16-bit selectable |
| SCC Channels | 3 | 3 | 3 | 3 | 3 | 3 |
| SMC Channels | 2 | 2 | 2 | 2 | 2 | 2 |
| Package Material | Ceramic PGA | Ceramic PGA | Ceramic PGA | Ceramic PGA | Ceramic PGA | Plastic PGA |
| Supply Voltage | 5 V | 5 V | 5 V | 5 V | 5 V | 5 V |
| Lifecycle | NRND (sustained for legacy) | NRND | NRND | NRND | NRND | NRND |
מבדילים עיקריים
- Integrated hardware protocol engine offloads CPU (לעומתMC68302CRC16C)
- Higher-speed 25 MHz option for headroom (לעומתMC68302CRC25C)
- Ceramic PGA for industrial/extended reliability (לעומתMC68302PV20C)
- NXP (post-Freescale) sustained production (לעומתMC68302CRC20C (predecessor label))
הערות תכנון
The 132-PGA package is through-hole only and not reflow-solderable on standard SMT lines; plan for a PGA socket (e.g., machine-pin or low-insertion-force socket) or hand-soldered through-hole assembly to enable field replacement. The 39.63 mm x 39.63 mm body requires significant PCB real estate compared with QFP alternatives - verify mechanical clearance against neighboring tall components. PGA pin-grid assignments follow the M68000 family convention; consult the package outline drawing for the exact pin-1 orientation and pad layout. Estimated: at 20 MHz the 132-PGA decoupling is critical; place 100 nF ceramic bypass caps within 5 mm of every VCC/GND pin pair on the IC's footprint.
The MC68302CRC20C157 requires the M68000-family power-sequencing discipline: VCC must ramp monotonically to 5 V with RESET held low until the supply stabilizes for at least 100 ms, otherwise the M68000 core may latch up or fetch from an invalid program address. The 5 V rail should be sourced from a low-impedance regulator (LDO or 7805-class) with bulk decoupling of at least 22 uF and 100 nF ceramic near each VCC pin. Estimated: at 20 MHz with all SCCs active and DMA running, worst-case supply current is around 250 mA; budget 500 mA headroom for in-rush and transient loading.
The 8/16-bit external data bus must be length-matched within 10 mm across D0-D15 to avoid skew at 20 MHz; route address and data buses over a continuous ground plane to minimize crosstalk into the SCC transmit lines. Place the system clock trace short and guarded by ground pour to prevent the 20 MHz fundamental from coupling into adjacent analog sections. The SCC serial lines (TXD/RXD) should be routed as 50-ohm controlled-impedance pairs when driving external cables. Estimated: total bus-cycle time at 20 MHz is 50 ns, so peripheral logic must respond within four clock cycles (DTACK) or the system will insert wait states that halve throughput.
Do not confuse MC68302 variants: the MC68302CRC20C157 differs from the MC68EN302 (Ethernet variant), MC68360 (different family with QUICC engine), and MC68SEC000 (lower-end 8/16/32-bit core). Always verify the exact MPN string when ordering spares because family members are NOT cross-compatible in firmware. Common mistake is treating the on-chip RISC communications processor as software-configurable when in fact the SCC mode registers must be programmed in a specific order during initialization to avoid spurious FIFO flags. Also note that legacy 5 V parts may need re-validation for modern EMC/ESD compliance when dropped into new chassis.
מידע על תאימות
MC68302CRC20C157 is a legacy 5 V ceramic PGA part designed in the pre-RoHS era; the original silicon is not RoHS compliant per the M68302 family datasheet. Lead-free and RoHS-compliant variants exist within the M68302 family but the C157 suffix variant was not flagged RoHS in the Verified Web Data. The part is not AEC-Q100 qualified (it is a legacy telecom part, not an automotive MCU). Compliance values marked unknown - request a C of C from Rochester Electronics before any new procurement.
