NXP Semiconductors MC68HC908JL8CFA

Overview

MC68HC908JL8CFA from NXP (formerly Freescale) is an 8-bit HCS08-core microcontroller with 8 KB on-chip Flash memory, 512 bytes RAM, and integrated peripherals including a 10-bit ADC, SCI serial interface, TIM module with PWM and input capture, and keyboard interrupt capability. It operates at up to 8 MHz bus frequency and supports 3.3 V or 5 V supply, targeting low-cost embedded control in appliance motor drives and industrial sensor nodes.

For engineers reviewing the MC68HC908JL8CFA datasheet, MC68HC908JL8CFA pinout, MC68HC908JL8CFA application, or MC68HC908JL8CFA equivalent, key selection considerations include its 28-pin SOIC package, internal RC oscillator with ±2% accuracy at 3.3 V, COP watchdog timer, LVI reset threshold of 2.7 V, and ROM-based monitor for in-system programming via SCI.

Technical Context

The MC68HC908JL8CFA implements the HCS08 CPU core with 16-bit address space, supporting indexed, extended, and relative addressing modes. Its System Integration Module (SIM) provides bus clock generation from either external crystal (1–8 MHz) or internal RC oscillator, with configurable prescalers and low-power wait/stop modes.

Peripheral integration includes a 10-channel 10-bit ADC with 4 selectable reference sources, a full-duplex SCI with programmable baud rate generator and framing error detection, and a dual-channel Timer Interface Module (TIM) supporting input capture, output compare, and buffered/unbuffered PWM - all synchronized to the same bus clock domain.

Key Specifications

Pinout & Package

MC68HC908JL8CFA is housed in a 28-pin SOIC (Small Outline Integrated Circuit) package with 0.3-inch body width and standard 1.27 mm pitch. Pin functions are defined per Freescale Document MC68HC908JL8 Rev. 3.1, Section 1.4.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC9RS08KA8, MC68HC908JL8CFA delivers proven KBI support and broader legacy toolchain compatibility; versus MC9S08QG8, it offers direct SOIC-28 footprint retention but trades off SPI/I²C and speed for design continuity in cost-sensitive replacements.

Availability

MC68HC908JL8CFA is available at Aetrix Electronics and suitable for home appliance control, industrial sensor nodes, smart power outlets, and legacy equipment retrofit requiring stable component supply and long-term obsolescence management.

Supply support for MC68HC908JL8CFA 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, specializing in secure connectivity solutions for automotive, industrial, and IoT markets.

The MC68HC908JL8CFA belongs to the legacy HCS08 microcontroller family designed for cost-sensitive, low-power embedded control applications where Flash programmability, integrated analog peripherals, and robust reset supervision are essential.

FAQ

What is the maximum operating frequency of the MC68HC908JL8CFA?

The MC68HC908JL8CFA supports a maximum bus clock frequency of 8 MHz at 5 V supply and 4 MHz at 3.3 V. This frequency determines instruction execution speed and peripheral timing margins. The actual achievable bus clock depends on oscillator source selection (XTAL or RC) and internal prescaler configuration. MC68HC908JL8CFA's timing specifications in Table 17-5 and Table 17-8 of Rev. 3.1 confirm these limits under specified voltage and temperature conditions.

Does the MC68HC908JL8CFA include a hardware watchdog timer?

Yes, the MC68HC908JL8CFA integrates a Computer Operating Properly (COP) watchdog timer with configurable timeout periods ranging from 1.8 ms to 2.3 s. It is enabled by default after reset and must be serviced regularly by firmware to prevent system reset. The COP module is documented in Chapter 14 of the MC68HC908JL8 Rev. 3.1 datasheet and operates independently of the main CPU clock domain.

Can the MC68HC908JL8CFA be programmed in-circuit without a dedicated programmer?

Yes, the MC68HC908JL8CFA contains a built-in Monitor ROM that enables in-system programming (ISP) via its SCI interface. Using standard UART signals (RxD/TxD), users can erase, program, and verify Flash memory without removing the device from the board. This capability is detailed in Chapter 7 of the MC68HC908JL8 Rev. 3.1 datasheet and requires only a simple level-shifting interface for 3.3 V or 5 V host communication.

What analog input capabilities does the MC68HC908JL8CFA provide?

The MC68HC908JL8CFA features a 10-bit successive-approximation ADC with 10 multiplexed input channels (AN0–AN9), selectable voltage references (V_REFH/V_REFL, AV_DD/AV_SS, internal bandgap), and conversion times as low as 12 µs per sample. Chapter 10 of the MC68HC908JL8 Rev. 3.1 datasheet specifies full-scale accuracy of ±1.5 LSB and integral nonlinearity of ±1 LSB across the operating temperature range.

Is the MC68HC908JL8CFA pin-compatible with other members of the HC08 family?

The MC68HC908JL8CFA shares the same 28-pin SOIC package and core pinout (e.g., V_DD, V_SS, RESET, IRQ, RxD, TxD, OSC1/OSC2) with MC68HC908JK8 and MC68HC08JL8, but differs in Flash size, RAM allocation, and peripheral enablement. Pin compatibility is confirmed in Section 1.4 of the MC68HC908JL8 Rev. 3.1 datasheet; however, functional equivalence requires verification of mask options and CONFIG register settings for each target variant.