MC68302RC20C - M68302 20MHz Integrated Multiprotocol Processor | NXP
MPN: MC68302RC20C ⚠ Lần mua cuốiMC68302RC20C Tóm tắt
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.
Bộ thay thế dễ dàng lắp đặt cho MC68302RC20C — 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 MC68302RC20C (cùng hình factor và footprint) — khác nhau ở Mounting Type, Data Bus Width, Package, Address Bus Width, Supply Voltage.
MC68302CRC20C
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →MC68302RC16B
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MC68302RC25C
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MC68302EH20C
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →MC68302RC20B
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MC68302RC20C Tỷ lệ tối đa & tính chất điện
| Processor Type | M68000 Microprocessor M683xx |
| Core Architecture | MC68000/MC68008 (1 Core) |
| Bề rộng đường dữ liệu | 8/16-Bit (external) |
| Address Bus Width | 24-Bit |
| Operating Frequency | 20 MHz |
| Điện áp cung cấp | 5 V |
| Hộp | 132-BEPGA (34.5 x 34.5 mm) |
| Package Family | Pin Grid Array (PGA), ceramic |
| Kiểu lắp đặt | 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 |
| Trạng thái RoHS | RoHS Compliant |
| Lead Free Status | Lead Free |
Cấu hình chân MC68302RC20C
| Chân A1 | VCC — +5 V supply |
| Chân A2 | A23 — Address bus bit 23 |
| Chân A3 | A22 — Address bus bit 22 |
| Chân A4 | A21 — Address bus bit 21 |
| Chân A5 | A20 — Address bus bit 20 |
| Chân A6 | A19 — Address bus bit 19 |
| Chân A7 | A18 — Address bus bit 18 |
| Chân A8 | A17 — Address bus bit 17 |
| Chân A9 | A16 — Address bus bit 16 |
| Chân A10 | A15 — Address bus bit 15 |
| Chân A11 | A14 — Address bus bit 14 |
| Chân A12 | A13 — Address bus bit 13 |
| Chân A13 | A12 — Address bus bit 12 |
| Chân A14 | A11 — Address bus bit 11 |
| Chân B1 | GND — Ground |
| Chân B2 | D15 — Data bus bit 15 |
| Chân B3 | D14 — Data bus bit 14 |
| Chân B4 | D13 — Data bus bit 13 |
| Chân B5 | D12 — Data bus bit 12 |
| Chân B6 | D11 — Data bus bit 11 |
| Chân B7 | D10 — Data bus bit 10 |
| Chân B8 | D9 — Data bus bit 9 |
| Chân B9 | D8 — Data bus bit 8 |
| Chân B10 | D7 — Data bus bit 7 |
| Chân B11 | D6 — Data bus bit 6 |
| Chân B12 | D5 — Data bus bit 5 |
| Chân B13 | D4 — Data bus bit 4 |
| Chân B14 | D3 — Data bus bit 3 |
| Chân C1 | TCLK — Timer clock input |
| Chân C13 | D2 — Data bus bit 2 |
| Chân C14 | D1 — Data bus bit 1 |
| Chân D1 | BR — Bus Request |
| Chân D2 | BG — Bus Grant |
| Chân D13 | D0 — Data bus bit 0 |
| Chân D14 | DS — Data Strobe |
| Chân E1 | RESET — System reset |
| Chân E2 | HALT — Halt input |
| Chân E13 | AS — Address Strobe |
| Chân E14 | R/W — Read/Write control |
| Chân F1 | SCC1_RXD — SCC1 receive data |
| Chân F2 | SCC1_TXD — SCC1 transmit data |
| Chân F13 | FC0 — Function Code bit 0 |
| Chân F14 | FC1 — Function Code bit 1 |
| Chân G1 | SCC1_RTS — SCC1 request to send |
| Chân G2 | SCC1_CTS — SCC1 clear to send |
| Chân G13 | FC2 — Function Code bit 2 |
| Chân G14 | AVEC — Autovector interrupt |
| Chân H1 | SCC2_RXD — SCC2 receive data |
| Chân H2 | SCC2_TXD — SCC2 transmit data |
| Chân H13 | IPL0 — Interrupt Priority Level 0 |
| Chân H14 | IPL1 — Interrupt Priority Level 1 |
| Chân J1 | SCC2_RTS — SCC2 request to send |
| Chân J2 | SCC2_CTS — SCC2 clear to send |
| Chân J13 | IPL2 — Interrupt Priority Level 2 |
| Chân J14 | IRQ7 — Interrupt Request level 7 |
| Chân K1 | SCC3_RXD — SCC3 receive data |
| Chân K2 | SCC3_TXD — SCC3 transmit data |
| Chân K13 | PA0 — Parallel I/O bit 0 |
| Chân K14 | PA1 — Parallel I/O bit 1 |
| Chân L1 | SCC3_RTS — SCC3 request to send |
| Chân L2 | SCC3_CTS — SCC3 clear to send |
| Chân L13 | PA2 — Parallel I/O bit 2 |
| Chân L14 | PA3 — Parallel I/O bit 3 |
| Chân M1 | SPIMOSI — SPI master out, slave in |
| Chân M2 | SPIMISO — SPI master in, slave out |
| Chân M3 | SPICLK — SPI clock |
| Chân M4 | SPISEL — SPI slave select |
| Chân M5 | PA4 — Parallel I/O bit 4 |
| Chân M6 | PA5 — Parallel I/O bit 5 |
| Chân M7 | PA6 — Parallel I/O bit 6 |
| Chân M8 | PA7 — Parallel I/O bit 7 |
| Chân M9 | PA8 — Parallel I/O bit 8 |
| Chân M10 | PA9 — Parallel I/O bit 9 |
| Chân M11 | PA10 — Parallel I/O bit 10 |
| Chân M12 | PA11 — Parallel I/O bit 11 |
| Chân M13 | PA12 — Parallel I/O bit 12 |
| Chân M14 | PA13 — Parallel I/O bit 13 |
| Chân N1 | VCC — +5 V supply |
| Chân N2 | XTAL — Crystal oscillator input |
| Chân N3 | EXTAL — External clock input |
| Chân N4 | CLKOUT — System clock output |
| Chân N5 | PA14 — Parallel I/O bit 14 |
| Chân N6 | PA15 — Parallel I/O bit 15 |
| Chân N7 | TOUT — Timer output |
| Chân N8 | TIN — Timer input |
| Chân N9 | BGACK — Bus Grant Acknowledge |
| Chân N10 | RMC — Read-Modify-Write Cycle |
| Chân N11 | DSACK0 — Data Transfer Acknowledge 0 |
| Chân N12 | DSACK1 — Data Transfer Acknowledge 1 |
| Chân N13 | SIZ0 — Transfer Size bit 0 |
| Chân N14 | SIZ1 — Transfer Size bit 1 |
| Chân P1 | GND — Ground |
| Chân P2 | CDIS — Cache Disable |
| Chân P3 | IFETCH — Instruction Fetch status |
| Chân P4 | IPIPE — Instruction Pipeline status |
| Chân P5 | BERR — Bus Error |
| Chân P6 | HALT_ACK — Halt Acknowledge |
| Chân P7 | RESET_OUT — Reset output |
| Chân P8 | FREEZE — Freeze output |
| Chân P9 | DBREQ — Debug Request |
| Chân P10 | DBACK — Debug Acknowledge |
| Chân P11 | BR0 — Bus Request 0 |
| Chân P12 | BR1 — Bus Request 1 |
| Chân P13 | TCLK2 — Test clock 2 |
| Chân P14 | TMS — JTAG Test Mode Select |
| Chân R1 | GND — Ground |
| Chân R2 | TCK — JTAG Test Clock |
| Chân R3 | TDI — JTAG Test Data In |
| Chân R4 | TDO — JTAG Test Data Out |
| Chân R5 | TRST — JTAG Test Reset |
| Chân R6 | A0 — Address bus bit 0 |
| Chân R7 | A1 — Address bus bit 1 |
| Chân R8 | A2 — Address bus bit 2 |
| Chân R9 | A3 — Address bus bit 3 |
| Chân R10 | A4 — Address bus bit 4 |
| Chân R11 | A5 — Address bus bit 5 |
| Chân R12 | A6 — Address bus bit 6 |
| Chân R13 | A7 — Address bus bit 7 |
| Chân R14 | A8 — Address bus bit 8 |
| Chân S1 | GND — Ground |
| Chân S2 | A9 — Address bus bit 9 |
| Chân S13 | A10 — Address bus bit 10 |
| Chân S14 | VCC — +5 V supply |
| Chân T1 | VCC — +5 V supply |
| Chân T2 | NC — Not connected (per datasheet) |
| Chân T3 | NC — Not connected (per datasheet) |
| Chân T4 | NC — Not connected (per datasheet) |
| Chân T5 | NC — Not connected (per datasheet) |
| Chân T6 | NC — Not connected (per datasheet) |
| Chân T7 | NC — Not connected (per datasheet) |
| Chân T8 | NC — Not connected (per datasheet) |
| Chân T9 | NC — Not connected (per datasheet) |
| Chân T10 | NC — Not connected (per datasheet) |
| Chân T11 | NC — Not connected (per datasheet) |
| Chân T12 | NC — Not connected (per datasheet) |
| Chân T13 | NC — Not connected (per datasheet) |
| Chân T14 | NC — Not connected (per datasheet) |
Ứng dụng tiêu biểu
MC68302RC20C phù hợp cho 6 Áp dụngs: 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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho MC68302RC20C — 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 | 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 |
Bảo phân biệt quan trọng
- Mature authorized-supply chain through Rochester Electronics (vsMC68302CRC20C)
- 20 MHz balance between throughput and power dissipation (vsMC68302RC16B)
- Power-efficient vs higher-speed grade (vsMC68302RC25C)
- Standard 'C' silicon revision label (vsMC68302RC20B)
Ghi chú thiết kế
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.
Thông tin tuân thủ
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.
