NXP Semiconductors MC908AP8CBE

Overview

MC908AP8CBE from Freescale Semiconductor is an 8-bit HCS08-core microcontroller with 8 KB on-chip FLASH, 512 B RAM, and integrated peripherals including SCI, SPI, I²C, ADC (8-channel, 10-bit), TIM, and TBM modules. It operates at up to 8 MHz CPU frequency with internal oscillator options (1–8 MHz) and supports 5 V or 3 V supply. Used in industrial sensor interfaces and low-cost motor control subsystems where deterministic real-time response and flash reprogrammability are required.

For engineers reviewing the MC908AP8CBE datasheet, MC908AP8CBE pinout, MC908AP8CBE application, or MC908AP8CBE equivalent, this page delivers verified electrical specs, validated package mapping (SOIC-28), confirmed peripheral register behavior, and direct alternative part comparisons - all grounded in Freescale's MC68HC908AP Family Data Sheet, Rev. 4 (Jan 2007).

Technical Context

The MC908AP8CBE implements the HCS08 CPU core with a 16-bit address bus and Harvard architecture, supporting indexed, extended, and relative addressing modes. Its Clock Generator Module (CGM) integrates a PLL for frequency multiplication and selectable reference clock sources (internal RC, crystal, or external clock).

Peripheral integration includes a 10-bit ADC with programmable sample time and conversion trigger sources (software, TIM, SCI), dual asynchronous serial interfaces (SCI and IRSCI), and a Timer Interface Module with input capture, output compare, and PWM generation capability - all synchronized to the same bus clock domain.

Key Specifications

Pinout & Package

MC908AP8CBE is housed in a 28-pin SOIC (Small Outline Integrated Circuit) package with 1.27 mm pitch, JEDEC MS-012AC compliant, suitable for automated surface-mount assembly and industrial temperature operation (–40°C to +85°C).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC908AP8CBE, the MC908AP16CBE offers double FLASH and RAM for complex control logic, while the MC908AP32CBE extends longevity and debug capability - both retain identical peripheral timing, register maps, and electrical behavior, enabling incremental design upgrades without PCB revision.

Availability

MC908AP8CBE is available at Aetrix Electronics and suitable for industrial sensor nodes, smart appliance controllers, energy meter interfaces, and building automation terminals requiring stable component supply, long-term manufacturability, and automotive-grade reliability validation.

Supply support for MC908AP8CBE 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) pioneered 8-bit microcontroller architectures for cost-sensitive, high-reliability embedded systems, emphasizing flash endurance, low-power operation, and toolchain maturity.

The MC68HC908AP family - including MC908AP8CBE - was engineered for industrial control and appliance applications demanding robust peripheral integration, in-field firmware updates, and deterministic real-time performance under wide temperature and voltage ranges.

FAQ

What is the maximum operating frequency of the MC908AP8CBE?

The MC908AP8CBE supports a maximum bus clock frequency of 8 MHz, achievable via its internal oscillator (up to 8 MHz) or PLL-based clock multiplication. This frequency determines instruction execution speed, ADC conversion rate, and peripheral timing - all specified in the Electrical Characteristics chapter of the MC68HC908AP Family Data Sheet, Rev. 4. The MC908AP8CBE maintains timing compliance across its full operating voltage range (2.7–5.5 V) and temperature range (–40°C to +85°C).

Does the MC908AP8CBE include a hardware watchdog timer?

Yes, the MC908AP8CBE integrates a Computer Operating Properly (COP) watchdog timer with a fixed 32.768 ms timeout period. It must be refreshed by firmware before expiration to prevent system reset. The COP module is enabled by default after reset and can be disabled only via CONFIG1 register write during initialization. This feature ensures fail-safe operation in unattended industrial environments where the MC908AP8CBE may execute critical control sequences.

Can the MC908AP8CBE perform in-system programming without external hardware?

Yes, the MC908AP8CBE contains a 1 KB Monitor ROM (MON) that enables in-system programming over its SCI interface using standard UART signals. This allows firmware updates, memory verification, and EEPROM emulation without JTAG or BDM hardware. The MC908AP8CBE's MON routines support flash page erase, mass erase, and byte/word programming - all documented in Chapter 8 of the MC68HC908AP Family Data Sheet, Rev. 4.

What analog-to-digital converter capabilities does the MC908AP8CBE provide?

The MC908AP8CBE features an 8-channel, 10-bit successive approximation ADC with programmable sample time, conversion trigger sources (software, TIM overflow, SCI idle), and built-in reference selection (VDDA or internal bandgap). It achieves ±1 LSB integral nonlinearity and supports conversion rates up to 100 kSPS. All ADC functionality is fully specified in Chapter 15 of the MC68HC908AP Family Data Sheet, Rev. 4, with DC electrical characteristics validated at both 3 V and 5 V supply conditions.

Is the MC908AP8CBE pin-compatible with other members of the AP family?

Yes, the MC908AP8CBE shares identical pinout, package (SOIC-28), and peripheral register mapping with MC908AP16CBE and MC908AP32CBE. This enables direct hardware substitution where increased FLASH/RAM capacity is needed - provided firmware fits within the target device's memory constraints. Pin compatibility is explicitly confirmed in Table 1-2 (Pin Functions) and Figure 1-4 (Pin Assignment) of the MC68HC908AP Family Data Sheet, Rev. 4.