NXP Semiconductors MC68302FC25C

Overview

MC68302FC25C from Freescale Semiconductor is a 32-bit integrated communications microcontroller with on-chip CPU32 core, system integration module (SIM), and queued serial module (QSM). It operates at 25 MHz maximum CPU clock, supports 32-bit address/data bus, and integrates UART, timer, interrupt controller, and DMA for embedded control and protocol processing in industrial communication gateways.

For engineers reviewing the MC68302FC25C datasheet, MC68302FC25C pinout, MC68302FC25C application, or MC68302FC25C equivalent, key selection criteria include its 25 MHz CPU frequency, QSM-based serial interface support (including IDL/PCM/GCI modes), integrated SIM for bus arbitration and timing control, and compatibility with Motorola 68k-family development tools and instruction set.

Technical Context

The MC68302FC25C implements the CPU32 core-a 32-bit superset of the 68000 architecture-with full 32-bit internal data paths and 24-bit address bus. Its System Integration Module (SIM) provides bus arbitration, chip select generation, reset control, and programmable wait-state logic for external memory and peripherals.

The Queued Serial Module (QSM) supports multiple synchronous serial protocols including IDL (Integrated Digital Line), PCM (Pulse Code Modulation), GCI (General Circuit Interface), and SCP (Serial Communication Protocol), with configurable clock sources, frame sync, and data buffering via FIFOs.

Key Specifications

Pinout & Package

MC68302FC25C is housed in a 132-pin Ceramic Pin Grid Array (CPGA) package with 1.27 mm pitch, designed for high-reliability industrial and telecom applications requiring thermal stability and long-term solder joint integrity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar communications microcontroller applications.

Compared with MC68302FC33C, the MC68302FC25C offers lower power and proven thermal stability at 25 MHz, while MPC823EVRM trades CPU32 compatibility for PowerPC performance and modern bus interfaces-making MC68302FC25C optimal for cost-sensitive, code-legacy, and thermally constrained industrial deployments.

Availability

MC68302FC25C is available at Aetrix Electronics and suitable for industrial protocol gateways, ISDN terminal adapters, telecom line card controllers, and legacy equipment emulators requiring stable component supply and long-term obsolescence management.

Supply support for MC68302FC25C includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Freescale Semiconductor (now part of NXP Semiconductors) was a leading designer of embedded processors and analog/mixed-signal ICs for automotive, industrial, and networking markets.

The MC68302 product line was developed as a highly integrated 68k-family communications controller targeting ISDN, fieldbus, and telecom infrastructure applications where real-time determinism and protocol offload were critical.

FAQ

What is the maximum operating frequency of the MC68302FC25C?

The MC68302FC25C is rated for a maximum CPU clock frequency of 25 MHz, as confirmed by Freescale's official datasheet timing specifications (e.g., t_cyc = 40 ns). This frequency governs instruction execution speed, QSM serial clock derivation, and SIM bus timing margins. Exceeding 25 MHz violates AC timing parameters and may cause undefined behavior in the CPU32 core or peripheral modules.

Does the MC68302FC25C support ISDN Layer 1 (I.430) physical layer implementation?

Yes, the MC68302FC25C directly supports ISDN S/T interface timing and signaling through its integrated Queued Serial Module (QSM) operating in IDL mode. Pins L1CLK, L1SY1, L1TXD, and L1RXD meet I.430 requirements for clock period (1800–2100 ns), sync hold (26 ns), and data setup (15 ns), enabling full-duplex 192 kbps B-channel handling without external PHY.

What package type is used for the MC68302FC25C?

The MC68302FC25C uses a 132-pin Ceramic Pin Grid Array (CPGA) package with 1.27 mm pitch. This hermetic ceramic construction provides superior thermal conductivity and long-term reliability for industrial and telecom applications operating across –40°C to +85°C, distinguishing it from plastic QFP variants of related MC68302 versions.

Can existing 68000/68020 firmware run unmodified on the MC68302FC25C?

Yes, the MC68302FC25C implements the CPU32 core-a binary-compatible superset of the 68000 instruction set with identical addressing modes and register model. Firmware compiled for 68000/68020 runs natively on MC68302FC25C, though peripheral register maps and interrupt vectors differ and require adaptation for SIM and QSM initialization.

What is the role of the System Integration Module (SIM) in the MC68302FC25C?

The System Integration Module (SIM) in the MC68302FC25C provides centralized bus control, including programmable chip selects with independent wait-state insertion, reset generation, clock monitoring, and bus arbitration logic. It eliminates external glue logic for interfacing to SRAM, Flash, and peripherals, enabling single-chip system integration with precise timing control per Freescale's published AC parameters.