NXP Semiconductors MC68HC000RC10

Overview

MC68HC000RC10 from Freescale Semiconductor (formerly Motorola) is a CMOS 16/32-bit microprocessor with 32-bit internal architecture, 16-bit data bus, and 24-bit address bus supporting up to 16 MB memory space. It operates at 10 MHz maximum clock frequency, features two privilege modes (User/Supervisor), and implements full M68000 instruction set compatibility. It was widely used in industrial controllers, early embedded workstations, and communications equipment requiring deterministic real-time execution.

For engineers reviewing the MC68HC000RC10 datasheet, MC68HC000RC10 pinout, MC68HC000RC10 application, or MC68HC000RC10 equivalent, key selection considerations include its 68-pin QFP package, asynchronous bus timing with DTACK handshaking, dual-mode exception handling, and compatibility with legacy M68000 software ecosystems.

Technical Context

The MC68HC000RC10 implements the full M68000 instruction set architecture with 32-bit internal registers and ALU, but external data transfers occur over a 16-bit bidirectional data bus. Its bus interface supports fully asynchronous operation using DTACK, BERR, and HALT signals for flexible timing with diverse peripheral logic.

It features a 24-bit physical address bus (A0–A23), 16-bit data bus (D0–D15), and dedicated control lines including AS, DS, R/W, UDS, LDS, and interrupt request inputs (IPL0–IPL2). Exception processing uses a 256-entry vector table starting at address $000000, with stack frame formats defined per exception type.

Key Specifications

Pinout & Package

MC68HC000RC10 is housed in a 68-lead plastic quad flat pack (QFP) with 0.65 mm lead pitch and standard JEDEC MO-137AC outline. The package is RoHS-compliant and designed for surface-mount assembly on FR-4 PCBs with thermal relief pads.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16/32-bit microprocessor applications.

Compared with MC68000P10, MC68HC000RC10 delivers 90% lower static power and better thermal margin; compared with MC68EC000RC10, it retains full M6800 peripheral support for backward-compatible system upgrades.

Availability

MC68HC000RC10 is available at Aetrix Electronics and suitable for industrial PLC controllers, legacy communications terminals, embedded workstation baseboards, and test equipment front-end controllers requiring stable component supply and long-term obsolescence management.

Supply support for MC68HC000RC10 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, known for the M68K and Power Architecture families. It emphasized high-reliability, long-lifecycle components for industrial and automotive markets.

The MC68HC000 belongs to Freescale's M68000 family of 16/32-bit microprocessors, designed for deterministic real-time control, backward-compatible software migration, and robust operation in harsh industrial environments.

FAQ

What is the maximum operating frequency of the MC68HC000RC10?

The MC68HC000RC10 is rated for a maximum clock frequency of 10 MHz under commercial temperature conditions (0°C to +70°C). This specification is validated with proper decoupling, stable VCC, and compliant load capacitance on all clock-distributed nodes. Exceeding 10 MHz may result in undefined instruction execution or bus timing violations, as confirmed in Section 10.8 of the M68000 User's Manual.

Does the MC68HC000RC10 support 32-bit data operations?

Yes, the MC68HC000RC10 executes all 32-bit instructions internally using its full 32-bit ALU and register file, but external data transfers occur over a 16-bit bus (D0–D15). A 32-bit move therefore requires two consecutive bus cycles. This architectural choice maintains software compatibility with the original MC68000 while reducing pin count and board complexity.

Is the MC68HC000RC10 pin-compatible with the MC68000P10?

No, the MC68HC000RC10 is not pin-compatible with the MC68000P10. While both share the same 68-pin footprint, the RC10 uses a QFP package (Case 765A-05) with gull-wing leads, whereas the P10 uses a 64-pin DIP (Case 740-03). Signal assignments also differ: MC68HC000RC10 includes CMOS-specific control signals absent on the NMOS P10 variant.

What bus handshaking protocol does the MC68HC000RC10 use?

The MC68HC000RC10 uses an asynchronous bus protocol centered on the DTACK (Data Transfer Acknowledge) signal. External peripherals assert DTACK low to indicate readiness, allowing variable-length read/write cycles independent of clock frequency. This eliminates rigid timing constraints and enables interoperability with slow memory or custom logic without wait-state generators.

Can the MC68HC000RC10 execute code from 8-bit wide memory?

Yes, the MC68HC000RC10 can interface with 8-bit memory devices using its LDS/UDS (Lower/Upper Data Strobe) signals to select individual byte lanes on the 16-bit data bus. When accessing 8-bit peripherals, software must manage byte alignment explicitly, and the processor asserts only the relevant strobe-enabling mixed 8/16-bit memory maps in the same address space.