NXP Semiconductors MC908JK3ECDWER

Overview

MC908JK3ECDWER from NXP (formerly Freescale) is an 8-bit HCS08 microcontroller featuring 4 KB Flash, 192 B RAM, a 10-bit ADC with 8 channels, a 16-bit TIM module with input capture/output compare/PWM, and on-chip COP watchdog. It operates at up to 8 MHz bus frequency and supports 5 V operation in SOIC-20 package for embedded control in industrial sensors and appliance motor interfaces.

For engineers reviewing the MC908JK3ECDWER datasheet, MC908JK3ECDWER pinout, MC908JK3ECDWER application, or MC908JK3ECDWER equivalent, key selection criteria include Flash endurance (10k erase/write cycles), integrated LVI voltage monitor (trip point 4.0 V ±0.15 V), and KBI keyboard interrupt support for low-power touch interface wake-up.

Technical Context

The MC908JK3ECDWER implements the HCS08 CPU core with 16-bit address space, indexed addressing mode, and 72-instruction set optimized for deterministic real-time control. Its System Integration Module (SIM) provides configurable bus clock generation from internal RC or external crystal oscillator, with dedicated registers for reset status, break handling, and interrupt vector management.

Memory subsystem includes 4 KB on-chip FLASH with block protection and mass erase capability, 192 B RAM with automatic retention during Stop mode, and 256 B Monitor ROM for in-system programming via UART. Peripheral integration centers on TIM (two-channel 16-bit timer with buffered PWM), ADC (8-channel 10-bit SAR with software/hardware trigger), and dual I/O ports (Port A and Port B) with programmable pull-ups and data direction control.

Key Specifications

Pinout & Package

MC908JK3ECDWER is housed in a 20-pin SOIC package with 0.3 inch width, JEDEC MS-013AC compliant footprint, and lead-free RoHS-compliant termination.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC908JK1ECDWER, the MC908JK3ECDWER adds essential analog capability and memory headroom; versus S9KEAZ128AMLH, it offers drop-in replacement feasibility in legacy SOIC-20 layouts but trades raw compute power for deterministic 8-bit real-time response.

Availability

MC908JK3ECDWER is available at Aetrix Electronics and suitable for industrial sensor nodes, home appliance motor controllers, smart thermostat interfaces, and LED lighting dimmer modules requiring stable component supply across multi-year production cycles.

Supply support for MC908JK3ECDWER 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 leader focused on secure connectivity solutions for automotive, industrial, and IoT applications.

The MC908JK3ECDWER belongs to the legacy HCS08 microcontroller family designed for cost-sensitive, low-power embedded control in appliances, sensors, and industrial equipment where deterministic real-time response and long-term supply stability are critical.

FAQ

What is the maximum operating frequency of the MC908JK3ECDWER?

The MC908JK3ECDWER supports a maximum bus clock frequency of 8 MHz, derived from either the internal RC oscillator (±2% accuracy) or an external crystal (up to 8 MHz). This determines instruction execution speed and peripheral timing resolution, with all timers and ADC conversions referenced to this clock domain. The MC908JK3ECDWER achieves consistent timing behavior across its specified operating voltage range of 4.5–5.5 V.

Does the MC908JK3ECDWER support in-system programming?

Yes, the MC908JK3ECDWER includes 256 B of Monitor ROM that enables UART-based in-system programming without external debug hardware. Using the TXD/RXDP and RXD/TXDP pins at 9600 bps, users can enter monitor mode via break signal detection and perform flash erase, program, and verify operations. This capability is fully implemented in the MC908JK3ECDWER silicon and documented in Section 9 of the technical data manual.

What is the function of the KBI module in the MC908JK3ECDWER?

The Keyboard Interrupt (KBI) module in the MC908JK3ECDWER provides hardware-assisted scanning of up to three Port B pins (PTB0–PTB2) to detect key presses and generate interrupts. It supports wake-up from Stop mode with minimal current draw, making it ideal for battery-powered remote controls or thermostats. The KBI logic is integrated into the MC908JK3ECDWER die and operates independently of CPU execution during sleep states.

How does the Low-Voltage Inhibit (LVI) feature operate in the MC908JK3ECDWER?

The LVI circuit in the MC908JK3ECDWER continuously monitors VDD and asserts a hardware reset when voltage drops below 4.0 V ±0.15 V. This action prevents unreliable operation due to marginal supply conditions and is active in all modes including Stop. The LVI threshold is factory-trimmed and fixed in the MC908JK3ECDWER; no configuration register adjusts this value.

Can the MC908JK3ECDWER generate PWM signals with dead-time control?

No, the MC908JK3ECDWER's TIM module supports standard buffered and unbuffered PWM generation but lacks dedicated dead-time insertion logic. Users must implement dead-time in firmware by sequencing complementary outputs with software delays or external logic. This limitation applies specifically to the MC908JK3ECDWER and is confirmed by the absence of dead-time control registers in Sections 10.5.4.1–10.5.4.3 of the technical data manual.