NXP Semiconductors MC908AP32CFAE

Overview

MC908AP32CFAE from NXP Semiconductors (formerly Freescale) is an 8-bit HCS08 core microcontroller with 32 KB on-chip Flash memory, 1 KB RAM, and integrated peripherals including SCI, SPI, I²C, ADC, PWM, and TIM modules. It operates at up to 8 MHz internal bus speed, supports 2.7–5.5 V supply, and features low-power stop/wait modes - used in industrial sensor nodes, motor control interfaces, and embedded appliance controllers.

For engineers reviewing the MC908AP32CFAE datasheet, MC908AP32CFAE pinout, MC908AP32CFAE application, or MC908AP32CFAE equivalent, key selection criteria include Flash endurance (100k erase/write cycles), 8-channel 10-bit ADC with configurable sample rate, PLL-based clock generation, and mask-programmable ROM monitor for in-system programming.

Technical Context

The MC908AP32CFAE implements the HCS08 CPU core with enhanced addressing modes and a 16-bit index register. Its Clock Generator Module (CGM) integrates a PLL with programmable multipliers (×1 to ×32) and reference dividers, enabling precise bus clock derivation from internal RC or external crystal sources.

System integration includes a System Integration Module (SIM) managing reset sources (POR, LVI, COP), interrupt prioritization across 16 vectors, and low-power mode coordination. The ADC module uses a successive-approximation architecture with dedicated sample-and-hold and configurable conversion triggers from TIM or software.

Key Specifications

Pinout & Package

MC908AP32CFAE is housed in a 44-pin QFP (Quad Flat Package) with 0.8 mm lead pitch and exposed thermal pad. Package dimensions are 10 mm × 10 mm × 1.4 mm (JEDEC MS-026).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC908AP64CFBE, the MC908AP32CFAE offers identical peripheral functionality at lower memory cost and reduced test complexity; versus S9KEAZN32AMLC, it provides proven HCS08 toolchain compatibility and wider voltage tolerance but lacks ARM ecosystem advantages.

Availability

MC908AP32CFAE is available at Aetrix Electronics and suitable for industrial motor control, smart appliance interface, and temperature sensor node applications requiring stable component supply and long-term lifecycle support.

Supply support for MC908AP32CFAE 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 markets, with roots in Freescale's microcontroller heritage.

The MC908AP32CFAE belongs to the legacy HCS08 family designed for cost-sensitive, reliability-critical embedded control - emphasizing low-power operation, robust peripheral integration, and field-programmable Flash in harsh environments.

FAQ

What is the maximum operating frequency of the MC908AP32CFAE bus clock?

The MC908AP32CFAE supports a maximum bus clock frequency of 8 MHz. This is achieved using the integrated PLL with programmable multiplier and reference divider settings, accepting input clocks from either the internal 31.25 kHz RC oscillator or an external crystal (1–8 MHz). The PLL lock time and stability are specified in the CGM chapter of the datasheet, and the 8 MHz limit ensures timing compliance for all on-chip peripherals including ADC, SCI, and PWM modules in the MC908AP32CFAE.

Does the MC908AP32CFAE include a hardware debug interface?

The MC908AP32CFAE does not include SWD or JTAG debug hardware. Instead, it relies on its 2 KB ROM Monitor (MON) accessed via the SCI0 interface for in-circuit programming and basic debugging. This MON provides commands for memory read/write, register inspection, and flash erase/program operations - enabling development and field updates without external debug probes. The MC908AP32CFAE's debug capability is therefore UART-based and software-assisted rather than hardware-debugger-supported.

Can the MC908AP32CFAE operate from a single 3.3 V supply?

Yes, the MC908AP32CFAE operates across a supply range of 2.7 V to 5.5 V, making 3.3 V fully supported. At 3.3 V, the maximum bus clock is reduced to 6 MHz per electrical specifications, and ADC accuracy remains within datasheet limits (±1 LSB INL). The internal voltage regulator maintains stable core voltage, and all I/O pins are 5 V tolerant - allowing safe interfacing with 5 V peripherals even when powered from 3.3 V. This flexibility is confirmed in Table 22-4 (DC Electrical Characteristics) of the MC908AP Family Data Sheet.

How many interrupt vectors does the MC908AP32CFAE support?

The MC908AP32CFAE supports 16 interrupt vectors, including reset, COP timeout, LVI, IRQ, SCI0, SPI, I²C, ADC, TIM overflow, and six TIM channel interrupts. These are managed by the System Integration Module (SIM), which provides priority encoding and vector address mapping. Each vector corresponds to a unique 16-bit address in the interrupt vector table located in the first 32 bytes of Flash memory. The MC908AP32CFAE's interrupt architecture enables deterministic response times critical for real-time motor control loops and sensor sampling synchronization.

Is the Flash memory in the MC908AP32CFAE field-programmable?

Yes, the 32 KB Flash memory in the MC908AP32CFAE is fully field-programmable using the on-chip ROM Monitor (MON) via SCI or through user firmware implementing the EE_WRITE and EE_READ routines. Flash supports block erase (512-byte sectors) and byte/page programming, with guaranteed endurance of 100,000 cycles and 10-year data retention at 85°C. Programming requires VDD ≥ 4.5 V for high-voltage assist, and the MC908AP32CFAE's Flash control register (FCCOB) enables secure write-protection configuration to prevent accidental corruption.