NXP Semiconductors MC908QT1ACDWER

Overview

MC908QT1ACDWER from Freescale Semiconductor is an 8-bit M68HC08 core microcontroller with 1 KB on-chip FLASH, 64 bytes RAM, and integrated ADC10, AWU, COP watchdog, LVI, and keyboard interrupt modules. It operates at up to 8 MHz bus frequency, supports 3.0–5.5 V supply, and targets low-cost industrial control and appliance timing applications.

For engineers reviewing the MC908QT1ACDWER datasheet, MC908QT1ACDWER pinout, MC908QT1ACDWER application, or MC908QT1ACDWER equivalent, this page delivers verified functional identity, validated package mapping (SOIC-16), confirmed security byte handling ($FFF6–$FFFD), and real-world use context for embedded firmware development and legacy system maintenance.

Technical Context

The MC908QT1ACDWER implements the M68HC08 CPU core with 16-bit address space, 8-bit data bus, and Harvard architecture memory organization. Its internal oscillator supports RC or crystal-based clocking with programmable trimming, and the SIM module enables dynamic clock source switching between INTCLK, RCCLK, and XTALCLK.

FLASH memory includes mass erase, page erase, and program operations with block protection via the FLASH Block Protect Register (FBPR). Security enforcement requires user-defined 8-byte pattern at $FFF6–$FFFD; monitor mode entry is denied if ≥5 bytes are zero - a hardware-level anti-dump feature confirmed in Rev. 3 Addendum (May 2012).

Key Specifications

Pinout & Package

MC908QT1ACDWER is housed in a 16-pin SOIC package (300 mil body width), compatible with standard SOIC-16 footprints and reflow soldering profiles. Pin assignments follow the MC68HC908QTA family layout with dedicated VDD/VSS, RESET, IRQ, KBI inputs, ADC channels, and I/O port pins.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68HC908QT2A and MC908QY1ACDWER, the MC908QT1ACDWER provides optimal cost/performance balance for fixed-function timers and keypad controllers where 1 KB FLASH and 4 ADC inputs are sufficient - reducing component cost without sacrificing reliability or debug security.

Availability

MC908QT1ACDWER is available at Aetrix Electronics and suitable for industrial timer control, appliance keypad interface, legacy metering subsystems, and low-cost motor start controllers requiring stable component supply across extended production lifecycles.

Supply support for MC908QT1ACDWER 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 cost-sensitive embedded applications, emphasizing robustness, low power, and toolchain maturity.

The MC68HC908QTA family - including MC908QT1ACDWER - was engineered for appliance, industrial control, and metering applications demanding high FLASH endurance, integrated analog peripherals, and secure firmware debugging.

FAQ

What is the maximum operating frequency of the MC908QT1ACDWER?

The MC908QT1ACDWER supports a maximum bus clock frequency of 8 MHz, derived from its internal RC oscillator (trimmable ±10%), external crystal (1–8 MHz), or ceramic resonator. At 8 MHz bus speed, instruction execution achieves ~2 million instructions per second (MIPS) with typical 2–4 cycle timing - sufficient for real-time control loops in timer and keypad applications. The MC908QT1ACDWER datasheet specifies timing parameters under 3.0–5.5 V supply conditions.

Does the MC908QT1ACDWER support in-circuit debugging?

Yes, the MC908QT1ACDWER supports monitor mode debugging via its built-in serial monitor interface, accessible through dedicated pins (e.g., MODA, MODB) and enabled by correct 8-byte security pattern at $FFF6–$FFFD. Monitor mode allows read/write access to memory and registers, but entry is blocked if five or more of those bytes are zero - a hardware security feature documented in the May 2012 Addendum to the MC68HC908QY4A datasheet. The MC908QT1ACDWER requires compatible Freescale BDM tools for full debug capability.

How many ADC channels does the MC908QT1ACDWER provide?

The MC908QT1ACDWER integrates a 10-bit ADC10 module with four analog input channels (AD0–AD3), multiplexed onto PORTA pins PA0–PA3. These channels support single-ended sampling with programmable conversion time and interrupt-on-complete functionality. While the broader QTA family includes variants with up to 8 ADC inputs, the MC908QT1ACDWER's 4-channel configuration is optimized for cost-sensitive applications like basic sensor monitoring or potentiometer reading in appliances.

What package type is used for the MC908QT1ACDWER?

The MC908QT1ACDWER is supplied in a 16-pin SOIC (Small Outline Integrated Circuit) package with 300 mil body width and standard 1.27 mm pitch. This RoHS-compliant surface-mount package matches footprint requirements of legacy MC68HC908QTA designs and supports automated assembly processes including reflow soldering. Pin assignments align with the family-wide SOIC-16 layout defined in Chapter 1.4 of the MC68HC908QYA/QTA Family Data Sheet, Rev. 3.

Is the MC908QT1ACDWER pin-compatible with other QTA family members?

Yes, the MC908QT1ACDWER shares identical SOIC-16 pinout with MC68HC908QT2A, MC68HC908QT4A, and MC908QY1ACDWER - enabling direct PCB reuse across variants. All QTA-series devices maintain consistent signal mapping for VDD/VSS, RESET, IRQ, KBI0–KBI3, AD0–AD3, and PORTA I/O. However, firmware must account for differences in FLASH size (1 KB vs. 2 KB/4 KB) and ADC channel count (4 vs. 8) - though register-level compatibility ensures minimal code adaptation.