NXP Semiconductors MC908AP64CFAER

Overview

MC908AP64CFAER from NXP Semiconductors (formerly Freescale) is an 8-bit HCS08 core microcontroller with 64 KB on-chip Flash, 2 KB RAM, and integrated peripherals including SCI, SPI, I²C, ADC, PWM, and TIM modules. It operates at up to 20 MHz CPU frequency, supports 2.7–5.5 V supply, and features low-power stop/wait modes - used in industrial sensor nodes and motor control interfaces where deterministic real-time response and EEPROM-like nonvolatile storage are required.

For engineers reviewing the MC908AP64CFAER datasheet, MC908AP64CFAER pinout, MC908AP64CFAER application, or MC908AP64CFAER equivalent, key selection criteria include its 64-pin LQFP package, 10-bit 16-channel ADC with 500 kHz–1 MHz clock constraint, internal PLL-based clock generation, and ROM-resident monitor for in-system programming without external debugger.

Technical Context

The MC908AP64CFAER implements the HCS08 CPU core with enhanced addressing modes and a 16-level hardware stack. Its Clock Generator Module (CGM) integrates a phase-locked loop (PLL) supporting programmable multiplication (×1 to ×32) and reference divider selection, 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 22 vectors, and low-power mode coordination. The ADC module uses a successive-approximation architecture with configurable sample time and conversion trigger sources (software, timer, or external pin).

Key Specifications

Pinout & Package

MC908AP64CFAER is housed in a 64-pin LQFP package with exposed thermal pad. Pin functions include dual power/ground pairs (VDD/VSS, VDDA/VSSA), dedicated oscillator pins (OSC1/OSC2), 52 general-purpose I/Os with interrupt-capable KBI inputs, and peripheral-specific signals for SCI, SPI, I²C, ADC, and TIM modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC908AP64CFAER, the MC9S08AW60CFUE adds CAN but removes ROM monitor and requires external programming infrastructure, while the S9KEAZ128AMLH offers ARM compatibility and memory headroom at the cost of legacy toolchain support and increased BOM complexity.

Availability

MC908AP64CFAER is available at Aetrix Electronics and suitable for industrial motor control, smart sensor node, home appliance UI controller, and power supply monitoring applications requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for MC908AP64CFAER 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 delivering secure, connected, and intelligent solutions for automotive, industrial, IoT, and mobile applications.

The MC908AP64CFAER belongs to the legacy HCS08 microcontroller family designed for cost-sensitive, resource-constrained embedded systems requiring high reliability, low power, and robust in-field programmability via ROM monitor.

FAQ

What is the maximum operating frequency of the MC908AP64CFAER?

The MC908AP64CFAER supports a maximum bus clock frequency of 20 MHz, derived from its internal PLL or external oscillator source. This corresponds to a CPU instruction rate of approximately 10 million instructions per second (MIPS) under typical conditions. The actual achievable frequency depends on supply voltage and temperature - for example, 20 MHz is guaranteed at 5.0 V and 25 °C, while 16 MHz is specified at 2.7 V. The MC908AP64CFAER datasheet defines timing parameters for all supported configurations.

Does the MC908AP64CFAER include a built-in bootloader?

Yes, the MC908AP64CFAER includes a 1 KB factory-programmed Monitor ROM (MON) that provides a UART-based bootloader. This allows in-system programming of Flash memory without external debug hardware - users can upload new firmware via SCI using simple ASCII commands. The MON supports read/write/erase operations, security byte configuration, and checksum verification. This feature is integral to the MC908AP64CFAER design and documented in Chapter 8 of its datasheet.

Can the MC908AP64CFAER operate from a 3.3 V supply?

Yes, the MC908AP64CFAER is fully specified for operation from 2.7 V to 5.5 V, making it compatible with standard 3.3 V systems. At 3.3 V, the maximum guaranteed bus clock is 16 MHz, and all I/O pins are 5 V tolerant when configured as inputs. The internal voltage regulator (VREG) can be enabled to supply 3.3 V to external circuitry. Electrical characteristics including ADC accuracy, propagation delays, and current consumption are validated across this full voltage range for the MC908AP64CFAER.

What packaging options are available for the MC908AP64CFAER?

MC908AP64CFAER is offered exclusively in a 64-pin LQFP package (10 mm × 10 mm, 0.5 mm pitch) with an exposed thermal pad. This RoHS-compliant package supports standard surface-mount assembly processes and provides adequate thermal dissipation for typical industrial operating conditions. No QFP, QFN, or die variants are listed in the official Freescale/NXP ordering information for the MC908AP64CFAER - the LQFP is the only production package.

How does the ADC module of the MC908AP64CFAER handle clock constraints?

The ADC module in the MC908AP64CFAER requires its clock to be set between 500 kHz and 1 MHz for accurate 10-bit conversions - a constraint explicitly defined in Revision 4 of the datasheet (page 254). This is enforced via the ADC Clock Control Register (ADCCN), where improper settings cause degraded linearity or missing codes. The clock is derived from the bus clock divided by a programmable prescaler. Designers must validate timing in their specific configuration, as violating this range directly impacts MC908AP64CFAER measurement fidelity.