NXP Semiconductors MC908JL8MDWE

Overview

MC908JL8MDWE from Freescale Semiconductor is an 8-bit HCS08-core microcontroller with 8 KB on-chip Flash memory, 512 B RAM, and integrated peripherals including a 10-bit ADC (8 channels), SCI serial interface, TIM timer module, and KBI keyboard interrupt controller. It operates at up to 8 MHz bus frequency, supports 2.7–5.5 V supply, and targets low-cost embedded control in automotive body electronics and industrial sensors.

For engineers reviewing the MC908JL8MDWE datasheet, MC908JL8MDWE pinout, MC908JL8MDWE application, or MC908JL8MDWE equivalent, this page delivers verified technical context, package-validated pin functions, real-world use cases, and two confirmed alternative parts - all grounded in Freescale's Rev. 3.1 datasheet and official ordering information.

Technical Context

The MC908JL8MDWE implements the HCS08 CPU core with enhanced addressing modes and a 16-bit index register, executing instructions at up to 8 MHz bus clock derived from internal RC or external crystal oscillator. Its System Integration Module (SIM) manages reset sources (POR, LVI, COP), low-power wait/stop modes, and interrupt prioritization across hardware IRQ, KBI, and SCI.

Peripherals are tightly coupled to I/O ports: the 10-bit ADC samples up to 8 analog inputs via PTA0–PTA7 pins with programmable conversion time; the SCI supports full-duplex asynchronous communication with baud rate generation tied to bus clock; and the TIM module provides input capture, output compare, and PWM on dedicated T1CH0/T1CH1 and T2CH0/T2CH1 pins.

Key Specifications

Pinout & Package

MC908JL8MDWE is housed in a 28-pin SOIC (Small Outline Integrated Circuit) package with 24 I/O pins, 2 power pins (VDD, VSS), and 2 oscillator pins (OSC1, OSC2). Pin assignments follow Freescale's standard HCS08 J-series layout, with multiplexed functions mapped per port register configuration.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC908JL8MDWE, MC908JK8CDWE trades KBI and Flash capacity for lower unit cost, while MC908JL3CDWE removes SCI entirely to reduce silicon area - both require firmware and PCB validation due to functional subset differences.

Availability

MC908JL8MDWE is available at Aetrix Electronics and suitable for automotive body control units, industrial sensor nodes, and medical device subsystems requiring stable component supply, long lifecycle support, and AEC-Q100-aligned reliability.

Supply support for MC908JL8MDWE 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, delivering scalable MCU platforms for automotive, industrial, and consumer applications.

The MC908JL8MDWE belongs to the HCS08 family - designed specifically for cost-sensitive, low-power 8-bit control applications requiring Flash programmability, mixed-signal integration, and automotive-grade robustness.

FAQ

What is the maximum operating frequency of the MC908JL8MDWE?

The MC908JL8MDWE supports a maximum bus frequency of 8 MHz, derived from its internal RC oscillator or external crystal source. This frequency governs instruction execution speed, ADC conversion rate, and SCI baud rate generation. The actual core clock is synchronized to the bus clock, and timing specifications in the Rev. 3.1 datasheet assume operation within this limit under 2.7–5.5 V supply conditions. Exceeding 8 MHz may result in undefined behavior or failure to meet AC timing parameters.

Does the MC908JL8MDWE include a hardware watchdog timer?

Yes, the MC908JL8MDWE integrates a Computer Operating Properly (COP) watchdog timer with configurable timeout ranging from 0.5 ms to 1.0 s. It is enabled by default after reset and must be serviced regularly via software writes to the COPCTL register to prevent system reset. The COP operates independently of the main clock source and remains active in wait mode, making it suitable for fail-safe embedded control in the MC908JL8MDWE.

Can the MC908JL8MDWE operate from a 3.3 V supply?

Yes, the MC908JL8MDWE is fully specified for operation from 2.7 V to 5.5 V, including standard 3.3 V systems. All I/O pins are 5 V tolerant when configured as inputs, and internal peripherals - including the 10-bit ADC, SCI, and TIM - maintain full functionality across this range. The Rev. 3.1 datasheet confirms electrical characteristics such as propagation delay, ADC accuracy, and COP timeout stability at 3.3 V.

How many analog input channels does the ADC in the MC908JL8MDWE support?

The MC908JL8MDWE features a 10-bit successive-approximation ADC with 8 dedicated analog input channels, mapped to PTA0 through PTA7. These pins are multiplexed with Port A digital I/O and require configuration via the ADCCFG register to enable analog mode. Conversion time is typically 14 µs at 8 MHz bus clock, and the ADC supports single-ended sampling referenced to VDD and VSS.

Is the MC908JL8MDWE pin-compatible with other HCS08 family members?

The MC908JL8MDWE shares the same 28-pin SOIC package and pin assignment with MC908JK8CDWE and MC908JL3CDWE, enabling mechanical drop-in replacement. However, functional compatibility requires verification: JK8 lacks KBI and has half the Flash/RAM, while JL3 omits the SCI module. Pinout alignment does not guarantee identical peripheral register maps or interrupt vectoring - firmware and schematic review is mandatory before substitution.