NXP Semiconductors MC908KX2CDWER

Overview

MC908KX2CDWER from Freescale Semiconductor is an 8-bit M68HC08 core microcontroller with 2 KB on-chip FLASH, 128 bytes RAM, and integrated 8-channel 8-bit ADC. It operates from 4.5 V to 5.5 V at –40°C to +125°C, features internal clock generator with DCO and PLL, keyboard interrupt module (KBI), and low-voltage inhibit (LVI) for automotive body control modules.

For engineers reviewing the MC908KX2CDWER datasheet, MC908KX2CDWER pinout, MC908KX2CDWER application, or MC908KX2CDWER equivalent, key selection criteria include its 2 KB FLASH size, 8-bit ADC resolution, IRQ1 external interrupt capability, KBI support for matrix keypad scanning, and SOIC-20 package compatibility with legacy HC08-based designs.

Technical Context

The MC908KX2CDWER implements the M68HC08 CPU core with 41-instruction set, supporting WAIT/STOP low-power modes and COP watchdog. Its ICG module includes a digitally controlled oscillator (DCO), modulo-N divider, frequency comparator, and digital loop filter for stable internal clock generation without external crystal.

It integrates a 8-channel single-ended ADC with programmable conversion time, keyboard interrupt module with configurable debounce, and external interrupt pin (IRQ1) with 19–43 kΩ internal pullup resistor. All I/O pins are CMOS-compatible with TTL-level inputs and open-drain outputs where applicable.

Key Specifications

Pinout & Package

MC908KX2CDWER is housed in a 20-pin SOIC (Small Outline Integrated Circuit) package with 0.3-inch body width and standard JEDEC MS-013AC footprint. Pin assignments follow the MC68HC908KX2 family layout defined in Section 1.4 of the datasheet.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC908KX8CDWER, the MC908KX2CDWER offers identical peripherals and timing behavior but reduced FLASH for cost-constrained implementations; versus MC9RS08KA2CSCR, it retains KBI and HC08 toolchain compatibility at the expense of newer core efficiency.

Availability

MC908KX2CDWER is available at Aetrix Electronics and suitable for automotive body electronics, industrial HMI panels, and appliance control systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MC908KX2CDWER 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 fabless semiconductor company specializing in microcontrollers, analog, and connectivity solutions for automotive, industrial, and consumer markets.

The MC908KX2CDWER belongs to the M68HC08 family, designed specifically for cost-sensitive, high-reliability embedded control applications requiring robust I/O, integrated analog functions, and extended temperature operation.

FAQ

What is the maximum operating frequency of the MC908KX2CDWER?

The MC908KX2CDWER supports a maximum internal bus frequency of 8 MHz, derived from its internal clock generator (ICG) with digitally controlled oscillator and PLL. This frequency is achievable across the full –40°C to +125°C temperature range when powered at 5.0 V ±10%. The actual system clock is configurable via ICG registers and may be divided down for lower-power operation.

Does the MC908KX2CDWER include a hardware UART or SCI module?

No, the MC908KX2CDWER does not integrate a Serial Communications Interface (SCI) module. It lacks dedicated UART hardware; serial communication must be implemented in software using GPIO pins and timer resources. This distinguishes it from higher-pin-count variants like the MC68HC908KX8, which includes a full SCI peripheral.

Can the MC908KX2CDWER operate without an external crystal?

Yes, the MC908KX2CDWER can operate without an external crystal. Its Internal Clock Generator (ICG) provides a fully functional DCO-based clock source with automatic trimming, enabling standalone operation. External crystal is optional and used only when higher frequency accuracy or stability is required.

What is the function of the PTA0–PTA4 pins on the MC908KX2CDWER?

The PTA0–PTA4 pins on the MC908KX2CDWER serve dual roles: general-purpose bidirectional I/O and Keyboard Interrupt Module (KBI) inputs KBD0–KBD4. Each pin includes an internal 24–48 kΩ pullup resistor and supports edge-triggered interrupts for matrix keypad scanning, reducing external component count in HMI designs.

Is the MC908KX2CDWER pin-compatible with the MC68HC908KX8?

No, the MC908KX2CDWER is not pin-compatible with the MC68HC908KX8. Although both belong to the same KX family and share the SOIC-20 package, the MC68HC908KX8 has additional I/O functionality assigned to pins reused for other purposes on the MC908KX2CDWER - notably, the absence of SCI and different PORTB signal mapping prevents direct substitution.