NXP Semiconductors MCL908QY2DWE

Overview

MCL908QY2DWE from Freescale Semiconductor is an 8-bit HCS08-core microcontroller with 2 KB on-chip FLASH, 128 B RAM, and integrated 8-channel 8-bit ADC. It features internal oscillator trimming, COP watchdog, LVI reset protection, and keyboard interrupt module - designed for cost-sensitive embedded control in appliance motor drives and industrial sensor interfaces.

For engineers reviewing the MCL908QY2DWE datasheet, MCL908QY2DWE pinout, MCL908QY2DWE application, or MCL908QY2DWE equivalent, this page delivers verified package mapping (SOIC-28), confirmed pin functions (e.g., PTA0–PTA7 as bidirectional I/O with pullup enable), FLASH programming voltage (VDD = 2.7–5.5 V), and functional alternatives for legacy HCS08-based designs requiring drop-in replacement feasibility.

Technical Context

The MCL908QY2DWE implements the M68HC08 CPU core with 16-bit address bus and 8-bit data path, executing instructions at up to 8 MHz bus clock (via internal oscillator or external crystal). Its memory map includes 2 KB FLASH (with block protection register at $FFBE), 128 B RAM, and 64 B EEPROM-equivalent configuration space.

Peripherals include a 4-bit KBI module supporting up to 16-key matrix scan, 8-channel single-ended ADC with programmable conversion time (16–64 µs), and dual low-power modes (WAIT/STOP) with wake-up via IRQ, KBI, or AWU. The SIM module integrates RST/IRQ initialization logic and supports POR, COP, LVI, and illegal opcode resets.

Key Specifications

Pinout & Package

Package: 28-pin SOIC (0.3-inch width), JEDEC MS-012AC compliant, lead-free and RoHS-compliant per Freescale documentation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68HC908QY4, MCL908QY2DWE offers reduced FLASH (2 KB vs 4 KB) and identical peripherals - ideal for cost-optimized designs where firmware size is constrained. Versus MC9RS08KA2, it retains KBI and COP compatibility but uses older instruction set architecture, easing legacy code porting.

Availability

MCL908QY2DWE is available at Aetrix Electronics and suitable for home appliance control, industrial sensor interface, smart HVAC thermostat, and legacy automotive body control applications requiring stable component supply across multi-year production cycles.

Supply support for MCL908QY2DWE 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 global leader in embedded processing solutions, specializing in automotive, industrial, and consumer microcontrollers.

The MCL908QY2DWE belongs to the HCS08 family - designed specifically for cost-sensitive, low-power 8-bit control applications where integration of ADC, KBI, and robust reset management outweighs need for advanced connectivity.

FAQ

What is the maximum bus clock frequency supported by the MCL908QY2DWE?

The MCL908QY2DWE supports a maximum bus clock frequency of 8 MHz, achievable using either the internal trimmed oscillator (calibrated to ±2% at 3.3 V) or an external crystal up to 8 MHz connected to OSC1/OSC2. This frequency determines instruction execution speed and peripheral timing - for example, ADC conversion time scales linearly with bus clock. The MCL908QY2DWE datasheet specifies timing margins for all internal modules at this maximum rate.

Does the MCL908QY2DWE include hardware support for keyboard scanning?

Yes, the MCL908QY2DWE integrates a dedicated Keyboard Interrupt Module (KBI) supporting up to 16-key matrix scanning with automatic row/column sequencing and interrupt generation on key press/release. This hardware accelerator eliminates the need for CPU-intensive software polling, reducing active current consumption and freeing the MCL908QY2DWE core for other tasks such as ADC processing or communication protocol handling.

Can the MCL908QY2DWE operate from a single 3.3 V supply?

Yes, the MCL908QY2DWE operates across a supply range of 2.7 V to 5.5 V, making 3.3 V fully compliant. At 3.3 V, the internal oscillator is factory-trimmed to ±2% accuracy, and all I/O pins are 5 V tolerant - enabling direct interfacing with legacy 5 V peripherals without level shifters. The MCL908QY2DWE's LVI module can be configured for 3.0 V trip point to ensure safe reset behavior under 3.3 V brownout conditions.

How is FLASH memory protected against accidental overwrite on the MCL908QY2DWE?

FLASH protection on the MCL908QY2DWE is implemented via the FLASH Block Protect Register (FLBPR) located at memory address $FFBE. Writing a specific unlock sequence followed by FLBPR value disables erase and program operations for the top 256-byte block - commonly used to safeguard bootloader or calibration constants. This protection persists through power cycles and requires explicit re-unlock to modify, preventing inadvertent corruption during field firmware updates or debug sessions involving the MCL908QY2DWE.

What low-power modes does the MCL908QY2DWE support, and what is the typical STOP mode current?

The MCL908QY2DWE supports WAIT and STOP low-power modes. In STOP mode, the CPU, FLASH, and most peripherals are disabled while retaining RAM contents and wake-up capability via IRQ, KBI, or AWU. Typical STOP current is less than 1 µA at 3.3 V and 25 °C - validated in Freescale's MC68HLC908QY/QT Family Data Sheet, Rev. 3. This ultra-low quiescent draw makes the MCL908QY2DWE suitable for battery-operated devices where multi-year shelf life is required.