NXP Semiconductors MC68EC060RC50

Overview

MC68EC060RC50 from Motorola is a 32-bit superscalar microprocessor designed for embedded control applications without floating-point or memory management units. It operates at 50 MHz, features 8 KB instruction and 8 KB data caches, supports 32-bit address/data buses, and implements the full M68000 instruction set. It targets cost-sensitive industrial controllers and communication protocol processors.

For engineers reviewing the MC68EC060RC50 datasheet, MC68EC060RC50 pinout, MC68EC060RC50 application, or MC68EC060RC50 equivalent, key selection factors include its cache coherency model, bus timing compliance with asynchronous/peripheral interfaces, absence of MMU/FPU hardware, and compatibility with legacy M68K toolchains and real-time OS kernels.

Technical Context

The MC68EC060RC50 implements a dual-pipeline integer unit with separate instruction fetch and operand execution stages, enabling concurrent instruction decode and ALU operation. Its cache architecture uses physically addressed, write-through data cache and Harvard-style instruction cache, both 4-way set associative with 16-byte line size.

Bus interface complies with synchronous/asynchronous transfer protocols via programmable bus control register (BUSCR), supports burst transfers, lock cycles, and snoop-based cache coherency. Address translation is disabled by default and cannot be enabled - unlike MC68060/MC68LC060, the MC68EC060 lacks MMU circuitry entirely.

Key Specifications

Pinout & Package

MC68EC060RC50 is housed in a 256-pin ceramic quad flat pack (CQFP) package with 0.65 mm pitch, compliant with MIL-STD-883 Class B thermal and mechanical specifications. Pin assignments follow Motorola's standard M68060 family layout, with dedicated address/data multiplexing, bus control, interrupt, and clock signals.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar embedded microprocessor applications.

Compared with MC68EC060RC50, the MC68EC040RC33 offers lower performance but greater maturity and broader third-party OS support, while the MPC823E provides modern peripheral integration at the cost of architectural discontinuity and requalification effort.

Availability

MC68EC060RC50 is available at Aetrix Electronics and suitable for industrial PLC controllers, telecom protocol processors, medical device monitors, and avionics display systems requiring stable component supply across extended product lifecycles.

Supply support for MC68EC060RC50 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

Motorola Semiconductor (now NXP Semiconductors) was a U.S.-based semiconductor pioneer known for the 68000 family and RF/power technologies before divesting its semiconductor business in 2004.

The MC68EC060RC50 belongs to Motorola's embedded 68k microprocessor line, engineered specifically for cost-sensitive, non-FPU, non-MMU real-time control applications where binary compatibility with legacy M68K codebases is essential.

FAQ

Does MC68EC060RC50 include a hardware floating-point unit?

No, the MC68EC060RC50 does not contain a floating-point unit. Unlike the MC68060 and MC68LC060, the EC variant omits FPU circuitry entirely. Floating-point operations must be performed in software using the integer unit, which impacts performance for math-intensive tasks. This design choice reduces silicon area, power consumption, and cost while maintaining full M68000 instruction set compatibility for integer workloads. The MC68EC060RC50 datasheet explicitly states FPU exclusion in Appendix B.

What is the maximum supported clock frequency for MC68EC060RC50?

The MC68EC060RC50 is rated for a maximum clock frequency of 50 MHz. This specification is validated under defined voltage (5.0 V ± 5%) and temperature (0°C to 70°C) conditions per Motorola's Electrical and Thermal Characteristics section. Exceeding 50 MHz may result in timing violations, especially in cache fill and bus arbitration sequences. The part does not contain an internal PLL; it requires a clean, low-jitter external 50 MHz clock source applied to the CLK pin.

Is MC68EC060RC50 pin-compatible with other M68060 family members?

Yes, the MC68EC060RC50 shares the same 256-pin CQFP package and pinout as the MC68060 and MC68LC060. Signal names, placement, and electrical characteristics (TTL-compatible levels, drive strength, timing) are identical across the family. However, functional differences exist: MDIS and CDIS pins behave identically, but unused FPU/MMU-related pins (e.g., FPERR, MMUERR) are no-connection (NC) on MC68EC060RC50 and must remain unconnected in PCB layout.

Does MC68EC060RC50 support virtual memory or memory protection?

No, the MC68EC060RC50 has no memory management unit and therefore provides no virtual memory translation, page protection, or supervisor/user mode memory separation. All addresses are physical, and the processor operates exclusively in supervisor mode. Memory protection must be implemented externally via bus controllers or ASICs. This is a deliberate architectural distinction from the MC68060 and MC68LC060, confirmed in Section 1.1.2 and Appendix B of the M68060 User's Manual.

What cache coherency mechanism does MC68EC060RC50 implement?

The MC68EC060RC50 uses a snoop-based cache coherency protocol. External agents (e.g., DMA controllers) assert the SNOOP signal during memory accesses; the processor monitors this line and invalidates cache lines matching the accessed address. This ensures data consistency between CPU caches and peripherals without requiring software cache maintenance for most I/O operations. The write-through data cache policy further simplifies coherency for memory-mapped peripherals.