NXP Semiconductors MC68360CEM25L

Overview

MC68360CEM25L from Freescale Semiconductor is a quad integrated communications controller (QUICC) combining a 32-bit CPU32+ core, System Integration Module (SIM60), and Communications Processor Module (CPM) for embedded telecom and industrial networking. It operates at 25 MHz, supports up to 4 MB of external memory via 32-bit address/data bus, and integrates four serial communication channels (SCC/SMC), dual DMA, and IEEE 1149.1 JTAG test access. It is used in protocol-transparent router line cards requiring deterministic real-time packet handling.

For engineers reviewing the MC68360CEM25L datasheet, MC68360CEM25L pinout, MC68360CEM25L application, or MC68360CEM25L equivalent, key selection considerations include its integrated CPM offloading serial protocol processing (HDLC, SDLC, UART, BISYNC), 8 KB dual-port RAM for CPU–CPM data exchange, and support for glueless system integration with standard M68000-family peripherals.

Technical Context

The MC68360CEM25L implements a tightly coupled dual-processor architecture: the CPU32+ executes host control code while the autonomous CPM handles time-critical serial communications using microcoded RISC engines. Its SIM60 provides memory management, interrupt arbitration, clock generation, and bus interface logic compliant with M68000 asynchronous timing.

It features a 32-bit multiplexed address/data bus (A31–A0/D31–D0), programmable chip select timing, dynamic bus sizing (8/16/32-bit transfers), and hardware support for burst reads/writes. The CPM includes four SCCs (each configurable as HDLC/SDLC/BISYNC/UART), two SMCs (for UART/IrDA), and a 16-channel DMA controller with priority arbitration.

Key Specifications

Pinout & Package

MC68360CEM25L is housed in a 256-pin Plastic Quad Flat Pack (PQFP) package with 0.65 mm lead pitch, compliant with JEDEC MS-026. Pin assignments are defined per Freescale's MC68360UM/AD Rev. 4 (Section 2.1).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68360RC25L, the MC68360CEM25L offers lower cost and smaller board area in commercial-grade PQFP packaging; compared with MPC860TBCZQ50D4, it retains legacy M68K toolchain compatibility and deterministic CPM microcode execution-but lacks integrated Ethernet PHY support.

Availability

MC68360CEM25L is available at Aetrix Electronics and suitable for telecom infrastructure, industrial protocol gateways, railway signaling systems, and secure SCADA RTUs requiring stable component supply across long product lifecycles.

Supply support for MC68360CEM25L 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, focused on automotive, industrial, and networking markets before its 2015 acquisition.

The MC68360CEM25L belongs to Freescale's QUICC family-designed specifically to relieve host CPUs from serial communications overhead in carrier-grade and mission-critical edge equipment.

FAQ

What is the maximum operating frequency of the MC68360CEM25L?

The MC68360CEM25L is rated for a maximum clock frequency of 25 MHz, as specified in Freescale's MC68360UM/AD Rev. 4, Section 10. This frequency governs both the CPU32+ core execution speed and the CPM microcode cycle rate, directly determining serial frame throughput and interrupt latency. Operation above 25 MHz is not guaranteed and may result in timing violations or undefined behavior.

Does the MC68360CEM25L support Ethernet connectivity natively?

No, the MC68360CEM25L does not include an integrated Ethernet MAC or PHY. It provides four SCCs and two SMCs for serial protocols (HDLC, SDLC, UART, BISYNC) only. To implement Ethernet, an external MAC (e.g., DP83840) and PHY must be connected via the 32-bit local bus, with driver software managing packet framing and DMA transfers-unlike later PowerQUICC devices that integrate FEC Ethernet controllers.

How is memory mapped for the dual-port RAM in the MC68360CEM25L?

The MC68360CEM25L allocates its 8 KB dual-port RAM at fixed addresses within the internal memory map: CPU accesses it at 0x0000_0000–0x0000_1FFF, while the CPM accesses the same physical memory at 0x0000_0000–0x0000_1FFF in its own address space. This mirrored mapping allows lock-free data exchange, with hardware-enforced coherency-no software semaphore is needed for basic buffer handoff between CPU and CPM tasks.

Can the MC68360CEM25L operate in slave mode for use as a peripheral controller?

Yes, the MC68360CEM25L supports slave (disable CPU32+) mode via the CONFIG0 pin, allowing it to function as a dedicated communications coprocessor under control of an external master CPU. In this mode, the CPU32+ core is halted, but the SIM60 and CPM remain fully operational-enabling use cases like offloading serial protocol stacks in multi-processor systems without modifying existing host firmware.

What debug interfaces are supported by the MC68360CEM25L?

The MC68360CEM25L supports two debug interfaces: IEEE 1149.1 JTAG (TCK/TMS/TDI/TDO/TRST) for boundary-scan testing and emulation, and Background Debug Mode (BDM) via BKPT/DSI/DSO/DSCLK pins for real-time non-intrusive debugging. BDM allows full register visibility, memory inspection, and breakpoint insertion without stopping CPM microcode execution-critical for validating real-time serial protocol behavior.