NXP Semiconductors MC908QY4AMDWE

Overview

MC908QY4AMDWE from Freescale Semiconductor is an 8-bit HCS08-core microcontroller with 4 KB Flash, 192 B RAM, 10-bit ADC, on-chip oscillator, COP watchdog, and AWU wake-up module - designed for cost-sensitive industrial control and appliance timing applications requiring low-power operation and embedded firmware security.

For engineers reviewing the MC908QY4AMDWE datasheet, MC908QY4AMDWE pinout, MC908QY4AMDWE application, or MC908QY4AMDWE equivalent, this page delivers verified technical context, validated pin functions, confirmed security byte handling at $FFF6–$FFFD, and real-world use cases in motor control interfaces and sensor-based monitoring systems.

Technical Context

The MC908QY4AMDWE implements the HCS08 CPU core with 16-bit address space, supports internal RC oscillator (1–8 MHz) and external crystal/RC clock sources, and features a programmable 10-bit ADC with 8 input channels and configurable sample time. Its Auto Wakeup Module (AWU) enables precise low-power sleep-to-wake intervals using internal or external clock references.

Security enforcement occurs during monitor mode entry: host must supply eight user-defined bytes matching locations $FFF6–$FFFD; entry is denied if five or more of those bytes are zero. FLASH protection includes mass erase disable and block-level write/erase lock via dedicated registers.

Key Specifications

Pinout & Package

MC908QY4AMDWE is housed in a 20-pin SOIC (MDW) package with 18 I/O pins, one VDD, and one VSS. Pin functions include dual-purpose port pins supporting GPIO, ADC inputs, KBI, IRQ, and TIM channels.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC908QY4AMDWE, the MC908QY2AMDWE offers cost reduction through memory scaling while preserving full compatibility, whereas the MC908QT4ACDWE trades KBI for SCI - making it functionally divergent for human-interface applications but viable for protocol-based control nodes.

Availability

MC908QY4AMDWE is available at Aetrix Electronics and suitable for motor control interfaces, sensor-based environmental monitors, industrial panel controllers, and appliance power management units requiring stable component supply and long-term industrial lifecycle support.

Supply support for MC908QY4AMDWE 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) pioneered 8-bit MCU architectures for industrial and automotive markets, emphasizing robustness, low-power design, and integrated analog peripherals.

The MC68HC908QYx family was engineered for cost-optimized embedded control in appliances, power tools, and building automation - prioritizing Flash security, wake-up precision, and mixed-signal integration in compact packages.

FAQ

What is the Flash memory size and type used in the MC908QY4AMDWE?

The MC908QY4AMDWE integrates 4 KB of on-chip SuperFlash® memory licensed from SST. This non-volatile memory supports in-system programming, block erase, and mass erase operations. It also enables EEPROM emulation through software routines, allowing data retention across power cycles without external memory chips. The MC908QY4AMDWE Flash architecture includes dedicated protection registers to prevent accidental overwrite or readout.

How does the security feature work during monitor mode entry for the MC908QY4AMDWE?

The MC908QY4AMDWE enforces a security check during monitor mode entry: the host must transmit eight bytes matching the user-programmed values stored at memory addresses $FFF6–$FFFD. If five or more of those bytes are $00, monitor mode entry is denied. This prevents unauthorized firmware extraction. Users must program these locations - even with dummy values - to avoid unintentional lockout, as blank locations default to $00.

What are the supported clock sources for the MC908QY4AMDWE?

The MC908QY4AMDWE supports three clock sources: an internal RC oscillator (trimmable 1–8 MHz), an external crystal (via XTAL/EXTAL pins, 32.768 kHz to 8 MHz), and an external RC network. Clock selection and switching between internal and external sources are controlled via the OSC module registers. BUSCLKX4 and BUSCLKX2 outputs provide derived clocks for peripheral synchronization and debug timing.

Does the MC908QY4AMDWE include a hardware watchdog timer, and how is it configured?

Yes, the MC908QY4AMDWE includes a Computer Operating Properly (COP) watchdog timer. It is enabled/disabled and timed via the COPCTL register, with selectable timeout intervals ranging from 0.5 ms to 1.0 s. The COP resets the MCU if not cleared within the selected window, preventing runaway code. It operates independently of the main clock source and remains active in wait mode but is disabled in stop mode.

What is the role of the Auto Wakeup Module (AWU) in the MC908QY4AMDWE, and what timing ranges does it support?

The AWU in the MC908QY4AMDWE generates a wake-up interrupt after a programmable delay, enabling ultra-low-power operation. Using either the internal RC oscillator or an external clock source, it supports wakeup intervals from approximately 1 ms to 16 seconds. This allows the MC908QY4AMDWE to remain in stop or wait mode between sensor readings or control updates - critical for extending battery life in portable or energy-harvesting applications.