MC68302AG20C - 20MHz M68300 Integrated Comm Processor | NXP
MPN: MC68302AG20C ✗ Cuối đờiMC68302AG20C Tóm tắt
What is an integrated communications processor? An integrated communications processor (ICP) combines a general-purpose CPU core with on-chip peripherals such as DMA engines, serial channel controllers, timers, and parallel ports that are tuned for protocol handling. The M68302 was the first device to offer a closely-coupled, industry-standard MC68000/MC68008 microprocessor core combined with a flexible communications architecture, placing it inside the broader taxonomy: microcontroller -> microprocessor -> integrated communications processor -> embedded networking SoC -> semiconductor.
Key features include up to three independent serial communications controllers (SCCs) supporting HDLC/SDLC, UART, and BISYNC protocols, a 2-channel DMA engine, 1152 bytes of on-chip dual-port RAM, a 24-bit address bus providing 16 MB of linear addressing, and an interrupt controller with up to seven external interrupt sources. The device operates from a single 5 V supply and supports a maximum CPU clock of 20 MHz.
The MC68302 architecture is built around a true 32-bit internal 68000 core running with a 16-bit external data bus, allowing engineers to reuse legacy 68000 firmware while gaining dedicated serial DMA offload. The on-chip RISC communications processor (CP) handles bit-level protocol work, freeing the core for higher-layer tasks. This dual-engine design was pioneering for early 1990s networking ASICs.
Typical applications include ISDN terminal adapters, ISDN modem modules, X.25 packet switches, industrial routers, factory-floor communication controllers, and legacy telecom backplane designs. The part also appears in industrial serial-bridge gateways and protocol-conversion adapters where deterministic SCC behaviour is required.
When designing with the MC68302AG20C, ensure proper bus arbitration and timing closure for the 20 MHz external clock. The SCC pins require external transceivers for RS-232/RS-485 connectivity. According to the NXP datasheet, decoupling must be placed close to the multiple VCC/GND pairs of the LQFP-144.
This page synthesizes distributor stock signals, EOL status, drop-in 68000-family alternatives, and design notes beyond what the manufacturer datasheet alone offers.
Bộ thay thế dễ dàng lắp đặt cho MC68302AG20C — 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 MC68302AG20C (cùng hình factor và footprint) — khác nhau ở Core Architecture, DMA Channels, RoHS Status, Data Bus Width, Maximum Clock Frequency.
MC68302AG16C
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →MC68302CFC20C
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MC68302AG20C Tỷ lệ tối đa & tính chất điện
| Core Architecture | M68000 / M68300 family |
| Bề rộng đường dữ liệu | 8/16-Bit external |
| Maximum CPU Clock | 20 MHz |
| Address Bus Width | 24-Bit (16 MB linear) |
| Core Count | 1 |
| On-Chip RAM | 1152 bytes dual-port |
| Serial Communications Controllers | 3 SCCs (HDLC/SDLC, UART, BISYNC) |
| DMA Channels | 2 |
| External Interrupts | Up to 7 sources |
| Điện áp cung cấp | 5 V |
| Hộp | 144-LQFP (20x20 mm) |
| Kiểu lắp đặt | Surface Mount |
| Trạng thái RoHS | Compliant |
| Lead-Free | Yes |
Hướng dẫn cấu hình chân MC68302AG20C 144-lqfp (20x20 mm)
Cấu hình chân cho MC68302AG20C (144-lqfp (20x20 mm) gói). IC số này bao gồm chân GPIO, giao diện truyền thông (UART, SPI, I2C) và chân nguồn. Tham khảo tài liệu thông số kỹ thuật của nhà sản xuất để biết các chức năng chân thay thế và tùy chọn cấu hình. Cực kỳ quan trọng cho thiết kế hệ thống tích hợp và lập trình PCB.
Không có dữ liệu chân cụ thể sẵn có cho MC68302AG20C.
Tham khảo: tài liệu kỹ thuật cho cấu hình chân đầy đủ.
Ứng dụng tiêu biểu
MC68302AG20C phù hợp cho 2 Áp dụngs: ISDN Terminal Adapter, Industrial Serial Router.
ISDN Terminal Adapter
The MC68302AG20C fits ISDN terminal adapters because its three on-chip serial communications controllers natively handle HDLC framing at the BRI S/T interface, and the 68000 core runs the higher-layer protocol stack without burdening bit-level work. Designers typically connect the SCC1 port directly to an external ISDN transceiver (Siemens PSB 2186 or equivalent), dedicating SCC2 and SCC3 to UART console and auxiliary data. The 20 MHz CPU clock provides enough headroom for full LAPD and PPP handling, while the 24-bit address bus maps the entire ISDN signalling memory space without bank switching. Compared with discrete 68000 plus separate SCC chip implementations, the integrated design reduces board area by roughly 40 percent and improves deterministic interrupt latency for real-time ISDN D-channel processing.
Được đề xuất
Industrial Serial Router
The MC68302AG20C's three SCCs allow simultaneous handling of three independent serial links (RS-232/RS-485) for protocol-conversion routing between fieldbus segments. The on-chip RISC communications processor offloads HDLC bit-stuffing and CRC, freeing the 68000 core for routing-table lookups and frame forwarding. Designers use DMA channel 1 to move received SCC frames directly into external SRAM, while the second DMA channel services the transmit side, achieving wire-speed throughput on 38.4 kbps to 2 Mbps serial links. The 1152-byte dual-port RAM is shared with the on-chip communications processor for descriptor passing. The 144-LQFP plastic package supports -40C to +85C industrial temperature operation as documented in NXP legacy datasheets.
