MC68302CRC20C157 - 20MHz M68000 IMP, 132-PGA | NXP
MPN: MC68302CRC20C157 ✗ Akhir HidupMC68302CRC20C157 Ringkasan
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.
Alternatif penggantian untuk MC68302CRC20C157 — 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 MC68302CRC20C157 (sama faktor bentuk dan footprint) — berbeda di dalam Mounting Type, Core Processor, DMA Channels, Data Bus Width.
MC68302CRC20C
✅ Drop-InKontak untuk harga
Lihat Datasheet →MC68302CFC20
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
MC68302CRC16C
✅ Drop-InKontak untuk harga
Lihat Datasheet →MC68302CRC25C
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
MC68302PV20C
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
MC68302CRC20C157 Rating Maksimal & Karakteristik Listrik
| Core Processor | M68000 |
| Number of Cores | 1 |
| Bus Width | 8-bit / 16-bit selectable |
| Internal Architecture | 32-bit |
| Frekuensi Bawah Maximum | 20 MHz |
| Tegangan Pemuat | 5 V |
| Package Type | 132-PGA (Pin Grid Array) |
| Package Dimensions | 39.63 mm x 39.63 mm |
| Tipe Mounting | 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) |
Konfigurasi Pin MC68302CRC20C157
| Pin produk 1 | A0 — Address bus bit 0 |
| Pin produk 2 | A1 — Address bus bit 1 |
| Pin produk 3 | A2 — Address bus bit 2 |
| Pin produk 4 | A3 — Address bus bit 3 |
| Pin produk 5 | A4 — Address bus bit 4 |
| Pin produk 6 | A5 — Address bus bit 5 |
| Pin produk 7 | A6 — Address bus bit 6 |
| Pin produk 8 | A7 — Address bus bit 7 |
| Pin produk 9 | A8 — Address bus bit 8 |
| Pin produk 10 | A9 — Address bus bit 9 |
| Pin produk 11 | A10 — Address bus bit 10 |
| Pin produk 12 | A11 — Address bus bit 11 |
| Pin produk 13 | A12 — Address bus bit 12 |
| Pin produk 14 | A13 — Address bus bit 13 |
| Pin produk 15 | A14 — Address bus bit 14 |
| Pin produk 16 | A15 — Address bus bit 15 |
| Pin produk 17 | A16 — Address bus bit 16 |
| Pin produk 18 | A17 — Address bus bit 17 |
| Pin produk 19 | A18 — Address bus bit 18 |
| Pin produk 20 | A19 — Address bus bit 19 |
| Pin produk 21 | D0 — Data bus bit 0 (8/16-bit mode) |
| Pin produk 22 | D1 — Data bus bit 1 |
| Pin produk 23 | D2 — Data bus bit 2 |
| Pin produk 24 | D3 — Data bus bit 3 |
| Pin produk 25 | D4 — Data bus bit 4 |
| Pin produk 26 | D5 — Data bus bit 5 |
| Pin produk 27 | D6 — Data bus bit 6 |
| Pin produk 28 | D7 — Data bus bit 7 |
| Pin produk 29 | D8 — Data bus bit 8 (16-bit mode) |
| Pin produk 30 | D9 — Data bus bit 9 |
| Pin produk 31 | D10 — Data bus bit 10 |
| Pin produk 32 | D11 — Data bus bit 11 |
| Pin produk 33 | D12 — Data bus bit 12 |
| Pin produk 34 | D13 — Data bus bit 13 |
| Pin produk 35 | D14 — Data bus bit 14 |
| Pin produk 36 | D15 — Data bus bit 15 |
| Pin produk 37 | AS — Address Strobe |
| Pin produk 38 | DS — Data Strobe (active low) |
| Pin produk 39 | R/W — Read/Write control |
| Pin produk 40 | CS0 — Chip Select 0 |
| Pin produk 41 | CS1 — Chip Select 1 |
| Pin produk 42 | CS2 — Chip Select 2 |
| Pin produk 43 | CS3 — Chip Select 3 |
| Pin produk 44 | BR — Bus Request |
| Pin produk 45 | BG — Bus Grant |
| Pin produk 46 | BGACK — Bus Grant Acknowledge |
| Pin produk 47 | DTACK — Data Transfer Acknowledge (active low) |
| Pin produk 48 | IPL0 — Interrupt Priority Level 0 |
| Pin produk 49 | IPL1 — Interrupt Priority Level 1 |
| Pin produk 50 | IPL2 — Interrupt Priority Level 2 |
| Pin produk 51 | RESET — Reset (active low) |
| Pin produk 52 | HALT — Halt (active low) |
| Pin produk 53 | CLK — System Clock input |
| Pin produk 54 | VCC — +5 V power supply |
| Pin produk 55 | GND — Ground |
| Pin produk 56 | TXD1 — SCC1 Transmit Data |
| Pin produk 57 | RXD1 — SCC1 Receive Data |
| Pin produk 58 | RTS1 — SCC1 Request To Send |
| Pin produk 59 | CTS1 — SCC1 Clear To Send |
| Pin produk 60 | CD1 — SCC1 Carrier Detect |
| Pin produk 61 | TXD2 — SCC2 Transmit Data |
| Pin produk 62 | RXD2 — SCC2 Receive Data |
| Pin produk 63 | TXD3 — SCC3 Transmit Data |
| Pin produk 64 | RXD3 — SCC3 Receive Data |
| Pin produk 65 | PCMTXD — PCM Transmit Data |
| Pin produk 66 | PCMRXD — PCM Receive Data |
| Pin produk 67 | PCMCLK — PCM Clock |
| Pin produk 68 | PCMSYN — PCM Sync |
| Pin produk 69 | TCLK — Timer Clock |
| Pin produk 70 | TOUT1 — Timer Output 1 |
| Pin produk 71 | TOUT2 — Timer Output 2 |
| Pin produk 72 | TIN1 — Timer Input 1 |
| Pin produk 73 | TIN2 — Timer Input 2 |
| Pin produk 74 | P0 — Parallel I/O Port bit 0 |
| Pin produk 75 | P1 — Parallel I/O Port bit 1 |
| Pin produk 76 | P2 — Parallel I/O Port bit 2 |
| Pin produk 77 | P3 — Parallel I/O Port bit 3 |
| Pin produk 78 | P4 — Parallel I/O Port bit 4 |
| Pin produk 79 | P5 — Parallel I/O Port bit 5 |
| Pin produk 80 | P6 — Parallel I/O Port bit 6 |
| Pin produk 81 | P7 — Parallel I/O Port bit 7 |
| Pin produk 82 | DREQ0 — DMA Request 0 |
| Pin produk 83 | DREQ1 — DMA Request 1 |
| Pin produk 84 | DACK0 — DMA Acknowledge 0 |
| Pin produk 85 | DACK1 — DMA Acknowledge 1 |
| Pin produk 86 | DON0 — DMA Done 0 |
| Pin produk 87 | DON1 — DMA Done 1 |
| Pin produk 88 | RAS0 — DRAM Row Address Strobe 0 |
| Pin produk 89 | RAS1 — DRAM Row Address Strobe 1 |
| Pin produk 90 | CAS0 — DRAM Column Address Strobe 0 |
| Pin produk 91 | CAS1 — DRAM Column Address Strobe 1 |
| Pin produk 92 | WE — DRAM Write Enable |
| Pin produk 93 | OE — Output Enable |
| Pin produk 94 | AVEC — Autovector (active low) |
| Pin produk 95 | FC0 — Function Code 0 |
| Pin produk 96 | FC1 — Function Code 1 |
| Pin produk 97 | FC2 — Function Code 2 |
| Pin produk 98 | SIZE — Bus Size (0=8-bit, 1=16-bit) |
| Pin produk 99 | DSACK0 — Data Size Acknowledge 0 |
| Pin produk 100 | DSACK1 — Data Size Acknowledge 1 |
| Pin produk 101 | BERR — Bus Error (active low) |
| Pin produk 102 | VCC — +5 V power supply |
| Pin produk 103 | GND — Ground |
| Pin produk 104 | A20 — Address bus bit 20 |
| Pin produk 105 | A21 — Address bus bit 21 |
| Pin produk 106 | A22 — Address bus bit 22 |
| Pin produk 107 | A23 — Address bus bit 23 |
| Pin produk 108 | TXD_SMC1 — SMC1 Transmit Data |
| Pin produk 109 | RXD_SMC1 — SMC1 Receive Data |
| Pin produk 110 | TXD_SMC2 — SMC2 Transmit Data |
| Pin produk 111 | RXD_SMC2 — SMC2 Receive Data |
| Pin produk 112 | RTS_SMC1 — SMC1 Request To Send |
| Pin produk 113 | CTS_SMC1 — SMC1 Clear To Send |
| Pin produk 114 | VCC — +5 V power supply |
| Pin produk 115 | GND — Ground |
| Pin produk 116 | P8 — Parallel I/O Port bit 8 |
| Pin produk 117 | P9 — Parallel I/O Port bit 9 |
| Pin produk 118 | P10 — Parallel I/O Port bit 10 |
| Pin produk 119 | P11 — Parallel I/O Port bit 11 |
| Pin produk 120 | P12 — Parallel I/O Port bit 12 |
| Pin produk 121 | P13 — Parallel I/O Port bit 13 |
| Pin produk 122 | P14 — Parallel I/O Port bit 14 |
| Pin produk 123 | P15 — Parallel I/O Port bit 15 |
| Pin produk 124 | IRQ1 — External Interrupt 1 |
| Pin produk 125 | IRQ2 — External Interrupt 2 |
| Pin produk 126 | IRQ3 — External Interrupt 3 |
| Pin produk 127 | IRQ4 — External Interrupt 4 |
| Pin produk 128 | IRQ5 — External Interrupt 5 |
| Pin produk 129 | IRQ6 — External Interrupt 6 |
| Pin produk 130 | IRQ7 — External Interrupt 7 |
| Pin produk 131 | VCC — +5 V power supply |
| Pin produk 132 | GND — Ground |
Aplikasi Umum
MC68302CRC20C157 cocok untuk 6 aplikasis: 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.
Direkomendasikan
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.
Direkomendasikan
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.
Direkomendasikan
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.
Direkomendasikan
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.
Direkomendasikan
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.
Direkomendasikan
Ringkasan Produk Direkomendasikan
Data referensi engineering untuk MC68302CRC20C157 — pembandingan, panduan desain, dan informasi konformitas.
Panduan Pemilihan
Pembandingan dengan Alternatif
| Parameter Umum | Produk Ini | 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 |
Diferensiator Kunci
- Integrated hardware protocol engine offloads CPU (vsMC68302CRC16C)
- Higher-speed 25 MHz option for headroom (vsMC68302CRC25C)
- Ceramic PGA for industrial/extended reliability (vsMC68302PV20C)
- NXP (post-Freescale) sustained production (vsMC68302CRC20C (predecessor label))
Catatan Desain
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.
Informasi Konformitas
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.
