NXP Semiconductors MCHC908QT4CDWE

Overview

MCHC908QT4CDWE from NXP Semiconductors (formerly Freescale) is an 8-bit HCS08-core microcontroller with 4 KB Flash, 192 B RAM, and integrated 8-channel 8-bit ADC. It operates at up to 8 MHz bus frequency using an internal trimmed RC oscillator or external crystal, and features on-chip COP watchdog, LVI reset protection, and keyboard interrupt capability. It targets low-cost embedded control in appliance motor interfaces and industrial sensor nodes.

For engineers reviewing the MCHC908QT4CDWE datasheet, MCHC908QT4CDWE pinout, MCHC908QT4CDWE application, or MCHC908QT4CDWE equivalent, key selection criteria include its 16-pin SOIC-W package, 5 V operation, internal oscillator trim register (OSCTRIM), and support for WAIT/STOP low-power modes without external clock circuitry.

Technical Context

The MCHC908QT4CDWE implements the HCS08 CPU core with 16-bit address space, supporting indexed, extended, and relative addressing. Its memory map includes 4 KB of on-chip FLASH (with block protection), 192 B of RAM, and dedicated I/O register space mapped to $0000–$00FF.

It integrates a System Integration Module (SIM) managing clock generation (INTCLK, BUSCLKX2/X4), reset sources (power-on, LVI, COP), and interrupt vectoring. The ADC module supports single-ended conversions with programmable prescaler and conversion-complete interrupt, while the Auto Wakeup Module (AWU) enables periodic wake-from-WAIT via internal RC timer.

Key Specifications

Pinout & Package

Package: 16-pin SOIC-W (Wide Body), 7.5 mm body width, 1.27 mm lead pitch, RoHS-compliant matte tin lead finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC9RS08KA2CSC and MC9S08QG4CDTE, the MCHC908QT4CDWE offers unique KBI hardware acceleration and factory-trimmed RC oscillator stability ideal for cost-sensitive, button-driven 5 V systems where pin compatibility and minimal BOM are critical.

Availability

MCHC908QT4CDWE is available at Aetrix Electronics and suitable for appliance motor control, industrial sensor nodes, smart power outlets, and consumer remote control hubs requiring stable component supply across long-lifecycle production programs.

Supply support for MCHC908QT4CDWE 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

NXP Semiconductors is a global semiconductor company formed from the spin-off of Philips' semiconductor division, now headquartered in Eindhoven, Netherlands, with design centers worldwide.

The MCHC908QT4CDWE belongs to the legacy HCS08 microcontroller family designed for cost-optimized, low-power 8-bit embedded control in white goods, industrial I/O modules, and battery-operated peripherals.

FAQ

What is the maximum operating frequency of the MCHC908QT4CDWE?

The MCHC908QT4CDWE supports a maximum bus clock frequency of 8 MHz. This is achieved either by using the internal trimmed RC oscillator (factory-calibrated to 4.0 MHz ±2%, doubled internally) or by connecting an external crystal up to 8 MHz to the OSC1/OSC2 pins. The CPU executes instructions at bus clock speed, enabling sub-microsecond interrupt response times critical for real-time motor control loops.

Does the MCHC908QT4CDWE support in-circuit programming?

Yes, the MCHC908QT4CDWE supports in-circuit programming via the Background Debug Mode (BDM) interface using a standard BDM pod. Programming is performed through the BKGD pin (shared with PTA7), requiring only two connections (BKGD and VDD) plus ground. The on-chip FLASH supports full erase, page erase, and byte/word programming operations without high-voltage programming signals.

How does the keyboard interrupt (KBI) module function on the MCHC908QT4CDWE?

The KBI module on the MCHC908QT4CDWE monitors up to four inputs (PTA0–PTA3) for falling-edge transitions, enabling wake-from-WAIT on keypress without CPU intervention. It uses dedicated hardware to debounce and detect key events, storing status in the KBI status register (KBISC). This eliminates polling overhead and reduces average system current in battery-powered remotes and control panels.

What low-power modes are available on the MCHC908QT4CDWE?

The MCHC908QT4CDWE supports WAIT and STOP modes. In WAIT mode, the CPU halts but clocks remain active-peripherals like ADC and TIM continue operating, and wake events (IRQ, KBI, AWU) resume execution. In STOP mode, all clocks halt except the LVI and COP watchdog; wake occurs only on RESET or IRQ assertion, reducing current to ~0.5 µA. Both modes retain RAM contents except STOP with certain CONFIG1 settings.

Is the MCHC908QT4CDWE pin-compatible with other members of the QY/QT family?

No, the MCHC908QT4CDWE is not pin-compatible with MC68HC908QY4 or MC68HC908QT2 variants. While all share the 16-pin SOIC-W package, pin functions differ significantly-for example, PTA4 on MCHC908QT4CDWE is multiplexed as OSC2/BUSCLKX4, whereas on QY4 it serves as a general-purpose I/O only. Always consult the specific device's pin assignment table (Figure 1-2 in Rev. 6 datasheet) before substitution.