NXP Semiconductors MC68HC908QT4VPE

Overview

MC68HC908QT4VPE from Freescale Semiconductor is an 8-bit HCS08-core microcontroller with 4 KB on-chip FLASH, 192 B RAM, and integrated 8-channel 8-bit ADC. It features internal RC oscillator (4 MHz nominal), low-voltage inhibit (LVI), computer operating properly (COP) watchdog, and keyboard interrupt (KBI) module. Designed for cost-sensitive embedded control in appliance motor drives and industrial sensor interfaces.

For engineers reviewing the MC68HC908QT4VPE datasheet, MC68HC908QT4VPE pinout, MC68HC908QT4VPE application, or MC68HC908QT4VPE equivalent, key selection criteria include its 16-pin SOIC package, 5 V operation, internal oscillator trim capability, KBI wake-up support, and FLASH-based field programmability.

Technical Context

The MC68HC908QT4VPE implements the M68HC08 CPU core with 16-bit address bus and Harvard architecture. It executes instructions at up to 8 MHz bus clock derived from internal RC oscillator or external crystal, with configurable COP timeout and LVI reset thresholds.

Its peripheral set includes a 16-bit timer interface module (TIM) with input capture/output compare, 8-bit ADC with software-triggered conversion, and dual I/O ports (Port A and Port B) supporting interrupt-on-change and keyboard scan functionality.

Key Specifications

Pinout & Package

MC68HC908QT4VPE is housed in a 16-pin SOIC package with 1.27 mm pitch, 10.3 mm × 7.5 mm body size, and standard JEDEC MS-012AC outline.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit microcontroller applications.

Compared with MC68HC908QT2VPE and MC9RS08KA2CP, the MC68HC908QT4VPE provides higher FLASH density for complex control algorithms and unique KBI hardware that reduces wake-up latency and power consumption in human-interface applications.

Availability

MC68HC908QT4VPE is available at Aetrix Electronics and suitable for home appliance control, industrial sensor interface, consumer electronics remote, and basic industrial PLC I/O modules requiring stable component supply across long-lifecycle production programs.

Supply support for MC68HC908QT4VPE 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) is a fabless semiconductor company specializing in microcontrollers, analog, and connectivity solutions for automotive, industrial, and consumer markets.

The MC68HC908QT4VPE belongs to the M68HC08 QY/QT family - designed specifically for cost-optimized, low-pin-count embedded control applications requiring integrated analog peripherals and robust reset/watchdog features.

FAQ

What is the maximum bus clock frequency supported by the MC68HC908QT4VPE?

The MC68HC908QT4VPE supports a maximum bus clock frequency of 8 MHz. This is achieved using the internal RC oscillator (trimmed to 4 MHz nominal) with BUSCLKX4 enabled, or via external crystal/RC source configured for 8 MHz operation. Electrical specifications confirm stable operation up to 8 MHz across the full temperature and voltage range.

Does the MC68HC908QT4VPE include a hardware watchdog timer?

Yes, the MC68HC908QT4VPE includes a Computer Operating Properly (COP) watchdog module. It offers configurable timeout intervals from 0.5 ms to 1.0 s via the COPCTL register and supports disable-on-break for safe debugging. The COP must be serviced regularly in firmware to prevent system reset.

Can the MC68HC908QT4VPE operate without an external crystal?

Yes, the MC68HC908QT4VPE can operate using its internal RC oscillator alone. The factory-trimmed oscillator delivers 4 MHz ±2% accuracy at 5 V and 25°C. For applications requiring tighter timing stability, an external crystal (1–8 MHz) or RC network may be used instead.

What is the function of the OSCTRIM register in the MC68HC908QT4VPE?

The OSCTRIM register ($FFC0) in the MC68HC908QT4VPE stores a 6-bit value used to fine-tune the internal RC oscillator frequency. Writing to this register adjusts the oscillator's RC time constant, enabling users to calibrate frequency accuracy after manufacturing variations or temperature drift.

How many I/O pins does the MC68HC908QT4VPE provide in its 16-pin SOIC package?

The MC68HC908QT4VPE provides 12 usable I/O pins: Port A (PTA0–PTA7) offers 8 pins, and Port B (PTB0–PTB3) adds 4 more. Pins OSC1, OSC2/PTA4, RESET, IRQ, VDD, and VSS are dedicated or multiplexed functions not counted as general-purpose I/O.