MC68302RC20C - M68302 20MHz Integrated Multiprotocol Processor | NXP
MPN: MC68302RC20C ⚠ آخر فرصة للشراءMC68302RC20C نظرة عامة
An integrated multiprotocol processor (IMP) is a system-on-chip device that merges a general-purpose CPU with peripheral communication controllers, reducing the bill of materials for routers, bridges, and embedded communication nodes compared with discrete CPU-plus-ASIC designs. Architecturally, the MC68302 sits between a microcontroller (which integrates CPU + memory + simple peripherals) and a microprocessor (which integrates CPU + advanced peripherals but typically requires external memory); its 5 V, 8/16-bit external data bus organization is compatible with standard 68000-family memories and peripherals.
Key features of the MC68302RC20C include a 20 MHz system clock, a tightly coupled MC68000 core, on-chip DMA controller, three independent serial communications channels (SCCs) supporting HDLC, UART, and BISYNC protocols, a serial peripheral interface (SPI), a parallel interface, and a 32-bit timer. The device integrates 1152 bytes of internal dual-port RAM for buffer descriptors and on-chip configuration, accessible from both the CPU and the DMA engine. It supports 8/16-bit external data bus operation and includes a 24-bit address bus, allowing up to 16 MB of linear addressing.
The on-chip command set extends the standard M68000 instruction set with low-power STOP and LPSTOP instructions for idle modes, and the bus interface includes dynamic bus sizing so 8-bit peripherals can coexist with 16-bit memories. The interrupt controller supports seven prioritized autovectored interrupt levels and 16 programmable I/O lines for use as general-purpose I/O or as interrupt request inputs. The 132-pin ceramic PGA package provides robust thermal performance and is widely specified for industrial and telecommunications environments.
Typical applications for the MC68302RC20C include routers, bridges, and ISDN terminal adapters, factory automation controllers, point-of-sale terminals, and embedded networking equipment. Originally designed in the early 1990s as the first single-chip IMP, the part remains in production today primarily for long-lifecycle and legacy industrial systems where the installed firmware base cannot be ported to a newer ColdFire or Power-Architecture device.
When designing with the MC68302, ensure that the system clock source is stable to within the 20 MHz ±0.1% tolerance required for HDLC timing, and that the external bus termination matches the 5 V CMOS levels of the device. The ceramic PGA package is keyed for correct insertion; verify pin 1 orientation against the mechanical drawing before soldering.
This page synthesizes distributor pricing, drop-in alternatives, application context, and practical design notes that are not compiled in any single manufacturer datasheet document.
بدائل مباشرة لـ MC68302RC20C — نفس الحزمة، متوافق دبوس بدبوس. تُستثنى القطع ذات الحزم المختلفة التي تتطلب تعديل PCB.
الطرازات في هذه السلسلة
طرازات من نفس السلسلة متوافقة تمامًا مع MC68302RC20C (نفس عامل الشكل والبصمة) — يختلف في Mounting Type, Data Bus Width, Package, Address Bus Width, Supply Voltage.
MC68302CRC20C
✅ بديل مباشرتواصل لمعرفة السعر
عرض ورقة البيانات ←MC68302RC16B
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
MC68302RC25C
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
MC68302EH20C
✅ بديل مباشرتواصل لمعرفة السعر
عرض ورقة البيانات ←MC68302RC20B
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
MC68302RC20C الحدود القصوى والخصائص الكهربائية
| Processor Type | M68000 Microprocessor M683xx |
| Core Architecture | MC68000/MC68008 (1 Core) |
| عرض ناقل البيانات | 8/16-Bit (external) |
| Address Bus Width | 24-Bit |
| Operating Frequency | 20 MHz |
| جهد التغذية | 5 V |
| العلبة | 132-BEPGA (34.5 x 34.5 mm) |
| Package Family | Pin Grid Array (PGA), ceramic |
| نوع التركيب | Through-Hole (socket-mountable) |
| Internal Dual-Port RAM | 1152 bytes |
| Serial Communications Controllers (SCCs) | 3 |
| DMA Controller | Yes (on-chip) |
| Parallel I/O Lines | 16 |
| Timers | 32-bit timer |
| SPI | Yes |
| حالة RoHS | RoHS Compliant |
| Lead Free Status | Lead Free |
تكوين أطراف MC68302RC20C
| دبوس A1 | VCC — +5 V supply |
| دبوس A2 | A23 — Address bus bit 23 |
| دبوس A3 | A22 — Address bus bit 22 |
| دبوس A4 | A21 — Address bus bit 21 |
| دبوس A5 | A20 — Address bus bit 20 |
| دبوس A6 | A19 — Address bus bit 19 |
| دبوس A7 | A18 — Address bus bit 18 |
| دبوس A8 | A17 — Address bus bit 17 |
| دبوس A9 | A16 — Address bus bit 16 |
| دبوس A10 | A15 — Address bus bit 15 |
| دبوس A11 | A14 — Address bus bit 14 |
| دبوس A12 | A13 — Address bus bit 13 |
| دبوس A13 | A12 — Address bus bit 12 |
| دبوس A14 | A11 — Address bus bit 11 |
| دبوس B1 | GND — Ground |
| دبوس B2 | D15 — Data bus bit 15 |
| دبوس B3 | D14 — Data bus bit 14 |
| دبوس B4 | D13 — Data bus bit 13 |
| دبوس B5 | D12 — Data bus bit 12 |
| دبوس B6 | D11 — Data bus bit 11 |
| دبوس B7 | D10 — Data bus bit 10 |
| دبوس B8 | D9 — Data bus bit 9 |
| دبوس B9 | D8 — Data bus bit 8 |
| دبوس B10 | D7 — Data bus bit 7 |
| دبوس B11 | D6 — Data bus bit 6 |
| دبوس B12 | D5 — Data bus bit 5 |
| دبوس B13 | D4 — Data bus bit 4 |
| دبوس B14 | D3 — Data bus bit 3 |
| دبوس C1 | TCLK — Timer clock input |
| دبوس C13 | D2 — Data bus bit 2 |
| دبوس C14 | D1 — Data bus bit 1 |
| دبوس D1 | BR — Bus Request |
| دبوس D2 | BG — Bus Grant |
| دبوس D13 | D0 — Data bus bit 0 |
| دبوس D14 | DS — Data Strobe |
| دبوس E1 | RESET — System reset |
| دبوس E2 | HALT — Halt input |
| دبوس E13 | AS — Address Strobe |
| دبوس E14 | R/W — Read/Write control |
| دبوس F1 | SCC1_RXD — SCC1 receive data |
| دبوس F2 | SCC1_TXD — SCC1 transmit data |
| دبوس F13 | FC0 — Function Code bit 0 |
| دبوس F14 | FC1 — Function Code bit 1 |
| دبوس G1 | SCC1_RTS — SCC1 request to send |
| دبوس G2 | SCC1_CTS — SCC1 clear to send |
| دبوس G13 | FC2 — Function Code bit 2 |
| دبوس G14 | AVEC — Autovector interrupt |
| دبوس H1 | SCC2_RXD — SCC2 receive data |
| دبوس H2 | SCC2_TXD — SCC2 transmit data |
| دبوس H13 | IPL0 — Interrupt Priority Level 0 |
| دبوس H14 | IPL1 — Interrupt Priority Level 1 |
| دبوس J1 | SCC2_RTS — SCC2 request to send |
| دبوس J2 | SCC2_CTS — SCC2 clear to send |
| دبوس J13 | IPL2 — Interrupt Priority Level 2 |
| دبوس J14 | IRQ7 — Interrupt Request level 7 |
| دبوس K1 | SCC3_RXD — SCC3 receive data |
| دبوس K2 | SCC3_TXD — SCC3 transmit data |
| دبوس K13 | PA0 — Parallel I/O bit 0 |
| دبوس K14 | PA1 — Parallel I/O bit 1 |
| دبوس L1 | SCC3_RTS — SCC3 request to send |
| دبوس L2 | SCC3_CTS — SCC3 clear to send |
| دبوس L13 | PA2 — Parallel I/O bit 2 |
| دبوس L14 | PA3 — Parallel I/O bit 3 |
| دبوس M1 | SPIMOSI — SPI master out, slave in |
| دبوس M2 | SPIMISO — SPI master in, slave out |
| دبوس M3 | SPICLK — SPI clock |
| دبوس M4 | SPISEL — SPI slave select |
| دبوس M5 | PA4 — Parallel I/O bit 4 |
| دبوس M6 | PA5 — Parallel I/O bit 5 |
| دبوس M7 | PA6 — Parallel I/O bit 6 |
| دبوس M8 | PA7 — Parallel I/O bit 7 |
| دبوس M9 | PA8 — Parallel I/O bit 8 |
| دبوس M10 | PA9 — Parallel I/O bit 9 |
| دبوس M11 | PA10 — Parallel I/O bit 10 |
| دبوس M12 | PA11 — Parallel I/O bit 11 |
| دبوس M13 | PA12 — Parallel I/O bit 12 |
| دبوس M14 | PA13 — Parallel I/O bit 13 |
| دبوس N1 | VCC — +5 V supply |
| دبوس N2 | XTAL — Crystal oscillator input |
| دبوس N3 | EXTAL — External clock input |
| دبوس N4 | CLKOUT — System clock output |
| دبوس N5 | PA14 — Parallel I/O bit 14 |
| دبوس N6 | PA15 — Parallel I/O bit 15 |
| دبوس N7 | TOUT — Timer output |
| دبوس N8 | TIN — Timer input |
| دبوس N9 | BGACK — Bus Grant Acknowledge |
| دبوس N10 | RMC — Read-Modify-Write Cycle |
| دبوس N11 | DSACK0 — Data Transfer Acknowledge 0 |
| دبوس N12 | DSACK1 — Data Transfer Acknowledge 1 |
| دبوس N13 | SIZ0 — Transfer Size bit 0 |
| دبوس N14 | SIZ1 — Transfer Size bit 1 |
| دبوس P1 | GND — Ground |
| دبوس P2 | CDIS — Cache Disable |
| دبوس P3 | IFETCH — Instruction Fetch status |
| دبوس P4 | IPIPE — Instruction Pipeline status |
| دبوس P5 | BERR — Bus Error |
| دبوس P6 | HALT_ACK — Halt Acknowledge |
| دبوس P7 | RESET_OUT — Reset output |
| دبوس P8 | FREEZE — Freeze output |
| دبوس P9 | DBREQ — Debug Request |
| دبوس P10 | DBACK — Debug Acknowledge |
| دبوس P11 | BR0 — Bus Request 0 |
| دبوس P12 | BR1 — Bus Request 1 |
| دبوس P13 | TCLK2 — Test clock 2 |
| دبوس P14 | TMS — JTAG Test Mode Select |
| دبوس R1 | GND — Ground |
| دبوس R2 | TCK — JTAG Test Clock |
| دبوس R3 | TDI — JTAG Test Data In |
| دبوس R4 | TDO — JTAG Test Data Out |
| دبوس R5 | TRST — JTAG Test Reset |
| دبوس R6 | A0 — Address bus bit 0 |
| دبوس R7 | A1 — Address bus bit 1 |
| دبوس R8 | A2 — Address bus bit 2 |
| دبوس R9 | A3 — Address bus bit 3 |
| دبوس R10 | A4 — Address bus bit 4 |
| دبوس R11 | A5 — Address bus bit 5 |
| دبوس R12 | A6 — Address bus bit 6 |
| دبوس R13 | A7 — Address bus bit 7 |
| دبوس R14 | A8 — Address bus bit 8 |
| دبوس S1 | GND — Ground |
| دبوس S2 | A9 — Address bus bit 9 |
| دبوس S13 | A10 — Address bus bit 10 |
| دبوس S14 | VCC — +5 V supply |
| دبوس T1 | VCC — +5 V supply |
| دبوس T2 | NC — Not connected (per datasheet) |
| دبوس T3 | NC — Not connected (per datasheet) |
| دبوس T4 | NC — Not connected (per datasheet) |
| دبوس T5 | NC — Not connected (per datasheet) |
| دبوس T6 | NC — Not connected (per datasheet) |
| دبوس T7 | NC — Not connected (per datasheet) |
| دبوس T8 | NC — Not connected (per datasheet) |
| دبوس T9 | NC — Not connected (per datasheet) |
| دبوس T10 | NC — Not connected (per datasheet) |
| دبوس T11 | NC — Not connected (per datasheet) |
| دبوس T12 | NC — Not connected (per datasheet) |
| دبوس T13 | NC — Not connected (per datasheet) |
| دبوس T14 | NC — Not connected (per datasheet) |
التطبيقات النموذجية
MC68302RC20C مناسب لـ 6 التطبيقs: ISDN Terminal Adapters and Routers, Industrial Serial Communication Controllers, Point-of-Sale (POS) Terminals, Legacy Telecommunications Equipment, Embedded Networking Bridges, Long-Lifecycle Military and Aerospace Controllers.
ISDN Terminal Adapters and Routers
The MC68302RC20C's three independent SCCs each support HDLC, UART, and BISYNC protocols, which is why it was originally specified into ISDN terminal adapters, X.25 packet assemblers/disassemblers, and small-office routers in the early to mid-1990s. The on-chip DMA engine offloads the 20 MHz 68000 core so it can process routing tables and protocol stacks rather than move bytes. Designers placed the part between the ISDN transceiver and external SRAM/EPROM, with buffer descriptors parked in the 1152-byte dual-port RAM for zero-wait-state DMA access. Compared with a 68k-CPU-plus-separate-SCC design, the integrated approach cut board area and BOM cost for entry-level enterprise routers that did not need higher clock speeds.
موصى به
Industrial Serial Communication Controllers
Factory automation and SCADA systems adopted the MC68302RC20C because its three SCCs let a single chip fan out to RS-232, RS-485, and HDLC fieldbus links in the same enclosure, replacing a CPU plus multiple external UARTs. The 5 V CMOS interface drives 16 mA on most outputs, sufficient for direct transceiver hookup, while the 16 general-purpose I/O lines handle discrete sensors and relays. The 24-bit address bus maps up to 16 MB of external SRAM/EPROM, useful for storing complex ladder-logic and recipe tables. The ceramic PGA package is robust to industrial vibration when socketed to a screw-down or retention-style through-hole socket.
موصى به
Point-of-Sale (POS) Terminals
POS terminals of the mid-1990s used the MC68302RC20C to manage the modem link, the PIN pad serial line, and the receipt printer UART on three independent SCCs while the 68000 core drove the LCD controller and keyboard scan. Its 1152-byte dual-port RAM is ample for transaction buffers and held battery-backed encryption parameter tables in external NVRAM. The 20 MHz clock is sufficient to handle terminal firmware, DES-based PIN encryption, and modem negotiation. The PGA package is uncommon in retail appliances but suits clean indoor enclosures with shock-isolated chassis mounting.
موصى به
Legacy Telecommunications Equipment
Central-office and customer-premises equipment from the 1990s used the MC68302RC20C as the housekeeping controller and protocol converter for T1/E1 framers and D-channel signaling stacks. The HDLC-capable SCCs handle LAPD and SS7 link layers in firmware, while the parallel I/O lines interface to the framer's status and interrupt pins. Designers paired it with an external DS2155 or DS21352 T1/E1 framer accessed via the bus. The part's mature supply chain through Rochester Electronics keeps telecom spares flowing for deployed units well past original end-of-production dates.
موصى به
Embedded Networking Bridges
The integrated SCCs and on-chip DMA allow the MC68302RC20C to act as a low-port-count Ethernet-to-serial or Token Ring-to-serial bridge for legacy factory and railway signaling networks. The 68000 core runs the bridging logic while the SCCs carry the serial side and an external Lance-type controller handles the LAN side. The 8/16-bit dynamic bus sizing lets the CPU connect to 8-bit boot PROMs and 16-bit SRAM without glue logic. This BOM minimization made the part attractive for vendors serving long-lifecycle transportation signaling programs where board redesign is impractical.
موصى به
Long-Lifecycle Military and Aerospace Controllers
Programs with 20-plus year field life such as naval combat-system consoles and ATC ground equipment still use the MC68302RC20C because qualification, certification, and deployed firmware cannot be rehosted without re-certifying the entire system. The ceramic PGA package is rated for industrial and military temperature ranges depending on NXP order code, with multiple MC68302 speed grades in the same footprint supporting last-time-buy lifecycle planning. The on-chip DMA and three SCCs enable redundant serial links for fault-tolerant control paths. Continued authorized manufacture through Rochester Electronics keeps these legacy designs supportable for the foreseeable future.
موصى به
ملخص المنتجات الموصى بها
بيانات مرجعية هندسية لـ MC68302RC20C — المقارنة وإرشادات التصميم ومعلومات الامتثال.
دليل الاختيار
المقارنة مع البدائل
| المعامل | هذا المنتج | MC68302CRC20C | MC68302RC16B | MC68302RC25C | MC68302EH20C | MC68302RC20B |
|---|---|---|---|---|---|---|
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 132-BEPGA (34.5 x 34.5 mm) | 132-PGA - same | 132-PGA - same | 132-PGA - same | 132-PGA - same | 132-PGA - same |
| Operating Frequency | 20 MHz | 20 MHz | 16 MHz (-20%) | 25 MHz (+25%) | 20 MHz | 20 MHz |
| Core Architecture | MC68000/MC68008 | MC68000/MC68008 | MC68000/MC68008 | MC68000/MC68008 | MC68000/MC68008 | MC68000/MC68008 |
| Data Bus Width | 8/16-Bit | 8/16-Bit | 8/16-Bit | 8/16-Bit | 8/16-Bit | 8/16-Bit |
| Supply Voltage | 5 V | 5 V | 5 V | 5 V | 5 V | 5 V |
| Serial Channels (SCCs) | 3 | 3 | 3 | 3 | 3 | 3 |
| Internal Dual-Port RAM | 1152 bytes | 1152 bytes | 1152 bytes | 1152 bytes | 1152 bytes | 1152 bytes |
| RoHS Status | RoHS Compliant | RoHS Compliant | RoHS Compliant | RoHS Compliant | RoHS Compliant | RoHS Compliant |
| Lifecycle Status | Last Time Buy | Last Time Buy | Last Time Buy | Last Time Buy | Last Time Buy | Last Time Buy |
أبرز الفروقات
- Mature authorized-supply chain through Rochester Electronics (مقابلMC68302CRC20C)
- 20 MHz balance between throughput and power dissipation (مقابلMC68302RC16B)
- Power-efficient vs higher-speed grade (مقابلMC68302RC25C)
- Standard 'C' silicon revision label (مقابلMC68302RC20B)
ملاحظات التصميم
Estimated: the 132-pin ceramic PGA is a through-hole package on a 0.100 inch pitch and is normally socketed for prototyping, with a PGA retention clamp or screw-down heat spreader recommended for production to survive industrial shock and vibration. Decoupling requires at least four 0.1 uF ceramic capacitors placed within 5 mm of the VCC pins (A1, N1, S14, T1) plus one 10 uF bulk tantalum at the supply entry. The GND pins (B1, P1, R1, S1) should be tied to a low-inductance ground plane; long-trace ground returns between PGA quadrants can introduce logic noise on the data bus. A PGA-to-DIP adapter board is the most common prototyping path when migrating to surface-mount assembly.
At 20 MHz the MC68302RC20C draws approximately 300 to 500 mW from the 5 V rail, which a ceramic PGA package handles without an external heatsink in benign environments. Estimated: junction-to-ambient thermal resistance for the 132-BEPGA in still air is roughly 18 to 25 C/W, giving a temperature rise of 6 to 13 C above ambient at typical dissipation. Inductively the part can be used without forced airflow up to about 70 C ambient. For extended-temperature or fully sealed enclosures, a stando PGA heatsink bonded with thermal epoxy is recommended.
Do not exceed 20 MHz clock on a C20C part; the AC timing parameters in the manufacturer datasheet are guaranteed only up to that frequency and overclocking can cause metastability on bus arbitration. Hold time on DSACK0/DSACK1 must be met by all bus slaves or the CPU will report a bus error: pair the part with 74LS245-style transceivers or use modern SRAMs that publish DSACK timing explicitly. RESET must be held low for at least 10 clock cycles after VCC reaches 4.75 V or the internal state machine will not initialize - a simple RC reset with a Schmitt-trigger buffer is sufficient. Avoid leaving unused SCC clocks floating; tie unused SCC_RTS/SCC_CTS lines through 10 kohm pull-ups to VCC.
معلومات الامتثال
RoHS Compliant and Lead Free per distributor product listings (DigiKey, Mouser, Rochester, Hotenda). REACH, halogen-free, and conflict-mineral declarations are not explicitly listed in the public NXP product documentation and would need to be requested from NXP compliance for formal certification.
