NXP Semiconductors MC705X32CFUE4

Overview

MC705X32CFUE4 from Freescale Semiconductor is a high-density HCMOS microcontroller unit featuring 32 KB on-chip ROM, 256 bytes RAM, 8-channel 8-bit ADC, Motorola CAN module (MCAN), and programmable timer with input capture/output compare. It operates at up to 4 MHz internal clock and supports STOP/WAIT/SLOW low-power modes. Used in automotive body control modules requiring integrated CAN communication and analog sensing.

For engineers reviewing the MC705X32CFUE4 datasheet, MC705X32CFUE4 pinout, MC705X32CFUE4 application, or MC705X32CFUE4 equivalent, key selection criteria include CAN protocol compliance, 8-bit ADC resolution and sampling rate, EEPROM endurance, oscillator configuration options (crystal/ceramic/external clock), and RESET/IRQ interrupt behavior under low-power modes.

Technical Context

The MC705X32CFUE4 implements the MC68HC05 CPU core with 11-bit address space, supporting single-chip and bootstrap operation modes. Its Motorola CAN module (MCAN) provides full CAN 2.0A compliance with transmit/receive buffers, acceptance filtering, and bus timing registers CBT0/CBT1 for configurable bit rates up to 1 Mbps.

It integrates dual pulse-length modulation (PLM) outputs via PLMA/PLMB registers, an 8-channel analog-to-digital converter with 8-bit resolution and conversion time ≤50 µs, and serial communications interface (SCI) with baud rate generator and wake-up capability via idle-line or address-mark detection.

Key Specifications

Pinout & Package

MC705X32CFUE4 is housed in a 64-pin QFP package with 0.5 mm pitch, measuring 14 mm × 14 mm. Pin assignments follow Freescale's MC68HC705X32 pinout specification, including dedicated CAN bus pins (RX0/TX0), analog inputs (PD0–PD7/AN0–AN7), and dual crystal oscillator connections (OSC1/OSC2).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC705X32CFUE4, MC68HC908GP32CP trades integrated CAN for FLASH flexibility and lower unit cost, while S9KEAZN32AMFK offers architectural modernization and expanded CAN capability at higher complexity and power consumption.

Availability

MC705X32CFUE4 is available at Aetrix Electronics and suitable for automotive body electronics, industrial CAN sensor nodes, motor interface modules, and diagnostic gateway applications requiring stable component supply and long-term lifecycle support.

Supply support for MC705X32CFUE4 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, analog, and mixed-signal ICs for automotive, industrial, and networking markets.

The MC68HC705X32 product line delivers cost-optimized, CAN-integrated 8-bit microcontrollers targeting legacy automotive subsystems and industrial control where deterministic real-time response and proven reliability are essential.

FAQ

What is the maximum operating frequency of the MC705X32CFUE4?

The MC705X32CFUE4 operates with an internal bus clock derived from an external crystal or resonator connected to OSC1/OSC2. Its maximum rated frequency is 4 MHz, corresponding to a 1 µs instruction cycle time for most instructions. This limit is defined by electrical specifications in Section 12 of the datasheet and applies across the full industrial temperature range (–40°C to +85°C). Exceeding this frequency may result in undefined behavior or timing violations in the MCAN or ADC subsystems.

Does the MC705X32CFUE4 include on-chip EEPROM memory?

No, the MC705X32CFUE4 does not integrate EEPROM. It features 32 KB of mask-programmed ROM and 256 bytes of RAM. Non-volatile parameter storage must be implemented externally using serial EEPROM or alternative solutions. Some variants in the MC68HC705 family (e.g., MC68HC705P6) include EEPROM, but the MC705X32CFUE4 specifically omits this feature as confirmed in the Memory and Registers chapter of its technical data manual.

How is CAN communication implemented on the MC705X32CFUE4?

CAN communication on the MC705X32CFUE4 is handled by the integrated MOTOROLA CAN Module (MCAN), compliant with CAN 2.0A. It uses dedicated RX0 and TX0 pins for logical-level CAN signals and requires an external CAN physical-layer transceiver (e.g., MC33290, TJA1040) to drive the differential bus. The MCAN includes transmit/receive buffers, acceptance filtering via CACC/CACM registers, and programmable bus timing through CBT0/CBT1 - enabling bit rates up to 1 Mbps.

What analog input voltage range does the MC705X32CFUE4 ADC support?

The MC705X32CFUE4 ADC accepts analog inputs between VRL and VRH reference pins, with typical operation at VRL = 0 V and VRH = 5 V. This establishes an 8-bit conversion range of 0–5 V full-scale, yielding ~19.5 mV per LSB. Input channels PD0–PD7 (AN0–AN7) are multiplexed into a single successive-approximation converter; conversion time is ≤50 µs under standard operating conditions, as verified in the Electrical Specifications section.

What power-saving modes are supported by the MC705X32CFUE4?

The MC705X32CFUE4 supports three low-power modes: STOP (current <10 µA), WAIT (CPU halted, peripherals active, RAM retained), and SLOW (internal clock divided by 2–8 for reduced dynamic power). STOP mode disables all clocks and preserves only register contents; WAIT mode maintains oscillator and peripheral clocks while freezing the CPU; SLOW mode dynamically scales clock frequency via the Miscellaneous Register. All modes are entered via specific instruction sequences documented in Section 2.2.