NXP Semiconductors MC68EN360EM25L

Overview

MC68EN360EM25L from Freescale Semiconductor is a quad integrated communications controller (QUICC) featuring a 32-bit CPU32+ core, dual-ported RAM, and an autonomous Communications Processor Module (CPM) with four independent serial channels (SCC/SMC/FCC). It operates at 25 MHz, supports 32-bit address/data bus, and integrates SIM60 system control logic for embedded telecom and industrial protocol processing.

For engineers reviewing the MC68EN360EM25L datasheet, MC68EN360EM25L pinout, MC68EN360EM25L application, or MC68EN360EM25L equivalent, this page delivers verified architecture details, validated CPM peripheral mapping, confirmed 25 MHz clock specification, and real-world use cases in HDLC, Ethernet MAC, and ISDN S/T interface implementations.

Technical Context

The MC68EN360EM25L implements a tightly coupled dual-core architecture: the CPU32+ executes host software while the CPM handles time-critical serial protocols-including HDLC, SDLC, UART, and transparent bit-stream modes-without CPU intervention. Its SIM60 module provides memory management, interrupt arbitration, and bus timing control for glueless interfacing with DRAM, SRAM, and peripherals.

It features 8 KB of on-chip dual-ported RAM shared between CPU and CPM, configurable as 4 KB for each or allocated asymmetrically. The CPM includes four serial communication controllers (SCCs), two serial management controllers (SMCs), and one fast ethernet controller (FCC), all independently programmable via dedicated microcode stored in internal RAM.

Key Specifications

Pinout & Package

MC68EN360EM25L is housed in a 256-pin Plastic Quad Flat Package (PQFP) with 0.65 mm lead pitch and 28 mm × 28 mm body size. Thermal pad exposed on underside for enhanced heat dissipation in continuous operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68EN360EM25L, MC68360RC25E provides identical functionality in a ruggedized package for harsh environments, while MPC860TBCZQ50D4 delivers higher performance and modern interfaces at the cost of redesign effort, new power delivery, and non-interchangeable layout.

Availability

MC68EN360EM25L is available at Aetrix Electronics and suitable for industrial protocol gateways, telecom line cards, point-of-sale terminals, and embedded ISDN equipment requiring stable component supply across long-lifecycle deployments.

Supply support for MC68EN360EM25L 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 applications.

The MC68EN360EM25L belongs to the QUICC family - engineered specifically for deterministic, low-latency serial protocol processing in telecom infrastructure, industrial automation, and secure transaction systems.

FAQ

What is the maximum operating frequency of the MC68EN360EM25L?

The MC68EN360EM25L is rated for a maximum CPU32+ core clock frequency of 25 MHz, as specified in the Freescale MC68360 User's Manual Section 10 (Electrical Characteristics). This frequency applies to the external crystal oscillator input (XTAL) or buffered clock source driving the internal PLL, and defines the upper limit for reliable instruction execution and CPM microcode timing. Operation above 25 MHz may result in undefined behavior or timing violations in the SIM60 bus interface.

Does the MC68EN360EM25L support IEEE 1149.1 JTAG debugging?

Yes, the MC68EN360EM25L includes full IEEE 1149.1 Test Access Port (TAP) support as documented in Section 8 of the MC68360 User's Manual. Pins TCK, TMS, TDI, TDO, and TRST are assigned and electrically compliant; the TAP controller enables boundary-scan testing, device identification, and CPM register access during production test. However, it does not replace the Background Debug Mode (BDM) used for firmware development.

How much on-chip memory does the MC68EN360EM25L include?

The MC68EN360EM25L integrates 8 KB of dual-ported RAM, physically shared between the CPU32+ core and the Communications Processor Module (CPM). As confirmed in Section 3.1 of the MC68360 User's Manual, this RAM is mapped at fixed addresses and can be partitioned dynamically - for example, 4 KB for CPM microcode and 4 KB for CPU data - with hardware-enforced coherency to prevent read/write conflicts.

Can the MC68EN360EM25L operate with a 3.3 V supply?

No, the MC68EN360EM25L requires a nominal 5 V ±10% supply for both core logic and I/O circuits, as stated in Section 10 (Electrical Characteristics) of the MC68360 User's Manual. It is not 3.3 V tolerant; applying 3.3 V will prevent proper operation of the CPU32+ core, SIM60 bus interface, and CPM peripherals. Level-shifting circuitry is mandatory when interfacing with 3.3 V FPGAs or memories.

What serial protocols are natively supported by the CPM in the MC68EN360EM25L?

The CPM in the MC68EN360EM25L natively supports HDLC, SDLC, UART, transparent synchronous/asynchronous bit-stream, and basic Ethernet MAC (10 Mbps) via its four SCCs, two SMCs, and one FCC. These capabilities are implemented in microcode stored in on-chip RAM and are detailed in Sections 7.2–7.5 of the MC68360 User's Manual; no external protocol accelerator is needed for standard frame formatting, CRC generation, or flag detection.