NXP Semiconductors MC908KX2CDWE

Overview

MC908KX2CDWE from Freescale Semiconductor is an 8-bit HCS08-core microcontroller with 2 KB on-chip FLASH, 128 B RAM, 8-channel 8-bit ADC, and integrated keyboard interrupt (KBI) module. It operates at up to 8 MHz internal bus frequency, supports 5 V operation, and features low-voltage inhibit (LVI), COP watchdog, and ICG clock generator with DCO and crystal support. Used in cost-sensitive industrial control panels and appliance user-interface modules.

For engineers reviewing the MC908KX2CDWE datasheet, MC908KX2CDWE pinout, MC908KX2CDWE application, or MC908KX2CDWE equivalent, this page delivers verified electrical specs, package mapping, functional role in embedded UI systems, and validated alternative options for legacy HCS08 migration paths.

Technical Context

The MC908KX2CDWE implements the HCS08 CPU core with a 16-bit address bus and Harvard architecture memory map. Its Internal Clock Generator (ICG) includes a digitally controlled oscillator (DCO), modulo-N divider, and frequency comparator enabling stable internal clock generation without external crystal - though crystal support (via OSC1/OSC2) is retained for precision timing.

It integrates a Keyboard Interrupt Module (KBI) supporting up to 5-key matrix scanning on PTA4–PTA0, plus an 8-channel 8-bit ADC with programmable conversion time and continuous mode. The device uses SuperFlash® technology for reliable in-system programmability and includes dedicated LVI circuitry with selectable trip points (4.25 V or 3.7 V) and hysteresis.

Key Specifications

Pinout & Package

MC908KX2CDWE is housed in a 20-pin SOIC (Small Outline Integrated Circuit) package with 300-mil body width and standard 0.050" lead pitch. Pin assignments follow Freescale's MC68HC908KX2 pinout layout per Data Sheet Rev. 2.1, Appendix A.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC908KX8CDWE, the MC908KX2CDWE trades FLASH capacity for lower cost and footprint in fixed-function UI roles; versus MC9RS08KA2CPD, it retains critical KBI hardware acceleration and HCS08 toolchain compatibility but lacks newer low-power modes.

Availability

MC908KX2CDWE is available at Aetrix Electronics and suitable for industrial control panels, home appliance user interfaces, and smart power outlet designs requiring stable component supply across extended product lifecycles.

Supply support for MC908KX2CDWE 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 MC908KX2CDWE belongs to the HCS08 family, designed specifically for cost-optimized, low-pin-count embedded user-interface applications with integrated analog and keyboard peripherals.

FAQ

What is the maximum operating frequency of the MC908KX2CDWE?

The MC908KX2CDWE supports a maximum internal bus frequency of 8 MHz, achievable using either the internal DCO (with appropriate ICG configuration and trimming) or an external crystal up to 8 MHz. The actual system clock depends on ICG multiplier and divider settings, and timing must be validated per application conditions including voltage and temperature.

Does the MC908KX2CDWE include an internal pullup resistor on the IRQ1 pin?

Yes, the MC908KX2CDWE includes an internal pullup resistor on the IRQ1 pin with a nominal value of 31 kΩ (min 19 kΩ, max 43 kΩ at 5 V and 25°C). This eliminates the need for an external pullup in most active-low interrupt configurations, simplifying board design.

Can the MC908KX2CDWE operate without an external crystal?

Yes, the MC908KX2CDWE can operate without an external crystal by using its internal Digitally Controlled Oscillator (DCO) as the system clock source. The DCO is factory-trimmed and further adjustable via the ICG Trim Register, enabling reliable operation across voltage and temperature ranges.

What is the ADC resolution and channel count of the MC908KX2CDWE?

The MC908KX2CDWE integrates an 8-bit successive-approximation ADC with 8 input channels (AD0–AD7), mapped to PTB0–PTB7 pins. Conversion time is programmable down to 12 µs per sample, and the module supports single-shot or continuous conversion modes with interrupt-on-complete capability.

Is the MC908KX2CDWE pin-compatible with other members of the KX series?

Yes, the MC908KX2CDWE is pin-compatible with the MC908KX8CDWE and MC68HC08KX8 in the 20-pin SOIC package. Shared pin assignments include VDD/VSS, OSC1/OSC2, IRQ1, PTA0–PTA4, and PTB0–PTB7, enabling direct substitution where FLASH size and peripheral requirements align.