NXP Semiconductors MC908AP64ACFBE

Overview

MC908AP64ACFBE from Freescale Semiconductor is an 8-bit HCS08-core microcontroller with 64 KB on-chip Flash memory, 2 KB RAM, and integrated peripherals including SCI, SPI, I²C, ADC, PWM, and a programmable PLL-based clock generator. It operates at up to 40 MHz core frequency and supports industrial temperature range (–40°C to +85°C) in a 64-pin LQFP package. It targets embedded control applications requiring deterministic real-time response and low-power operation.

For engineers reviewing the MC908AP64ACFBE datasheet, MC908AP64ACFBE pinout, MC908AP64ACFBE application, or MC908AP64ACFBE equivalent, key selection criteria include its 64 KB Flash density, 10-bit 16-channel ADC with hardware trigger support, PLL-configurable system clock up to 40 MHz, and integrated SIM module for unified reset/interrupt/low-power management.

Technical Context

The MC908AP64ACFBE 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) with programmable reference divider, VCO range select, and bandwidth control registers - enabling precise clock synthesis from internal RC or external crystal sources.

The System Integration Module (SIM) provides centralized control of reset sources (POR, LVI, COP, illegal opcode), interrupt prioritization across 27 vectors, and dual low-power modes (Wait and Stop) with configurable wake-up sources including IRQ, KBI, and TIM channels. The ADC supports 16 input channels with conversion times as low as 6.5 µs per sample at 1 MHz clock.

Key Specifications

Pinout & Package

MC908AP64ACFBE is housed in a 64-pin LQFP (10 mm × 10 mm, 0.5 mm pitch) package with exposed thermal pad. Pin assignments follow standard HCS08 AP-family layout, supporting multiplexed I/O, dedicated peripheral signals (SCI TX/RX, SPI MOSI/MISO/SCK/SS, I²C SDA/SCL), and analog inputs routed to ADC channels.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC908AP32ACFBE, the MC908AP64ACFBE provides double Flash capacity for complex control algorithms and data buffering; versus S9KEAZ128AMLH, it offers mature toolchain stability and lower gate count but lacks ARM ecosystem advantages and advanced peripherals like USB or DMA.

Availability

MC908AP64ACFBE is available at Aetrix Electronics and suitable for motor control, industrial sensor hubs, smart HVAC actuators, and energy metering interfaces requiring stable component supply across extended product lifecycles.

Supply support for MC908AP64ACFBE 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 solutions, specializing in automotive, industrial, and networking microcontrollers.

The MC908AP64ACFBE belongs to the HCS08 AP-family, designed specifically for cost-effective, low-power industrial control applications requiring robust analog integration, deterministic real-time response, and long-term supply assurance.

FAQ

What is the maximum operating frequency of the MC908AP64ACFBE?

The MC908AP64ACFBE achieves a maximum core frequency of 40 MHz using its integrated PLL-based Clock Generator Module. This frequency is derived from internal RC or external crystal sources with programmable multiplication factors (e.g., 4×, 8×). The actual achievable speed depends on VDD voltage and ambient temperature, with full 40 MHz operation guaranteed at 4.5–5.5 V and within the industrial temperature range. The MC908AP64ACFBE datasheet specifies AC electrical characteristics up to this rated speed.

Does the MC908AP64ACFBE support in-system programming (ISP)?

Yes, the MC908AP64ACFBE supports in-system programming via its built-in Monitor ROM, accessible through the SCI interface. This allows firmware updates without removing the device from the PCB. The monitor mode requires only two pins (TXD/RXD) and operates at configurable baud rates (e.g., 9600 or 19200 bps). Programming commands include page erase, byte/word write, and verification - all executed by the on-chip ROM code. No external high-voltage programmer is needed for basic ISP of the MC908AP64ACFBE.

What are the key differences between MC908AP64ACFBE and MC908AP32ACFBE?

The MC908AP64ACFBE and MC908AP32ACFBE share identical packaging (64-pin LQFP), peripheral sets (SCI, SPI, I²C, ADC, PWM), and core architecture. Their primary difference is Flash memory size: 64 KB vs. 32 KB. Both devices use the same mask option register (MOR) configuration and pin-compatible layout. The MC908AP64ACFBE also includes additional Flash protection blocks and extended block erase capabilities documented in Chapter 2.5 of the MC908AP64ACFBE datasheet.

How does the Low-Voltage Inhibit (LVI) function protect the MC908AP64ACFBE during brown-out conditions?

The LVI circuit in the MC908AP64ACFBE continuously monitors VDD and asserts a reset when voltage falls below a threshold of 2.5 V (typical) - preventing unreliable CPU operation and unintended Flash writes. This reset is synchronous with the internal clock and holds until VDD rises above the release threshold (~2.7 V). The LVI is enabled by default after power-on reset and can be disabled only via CONFIG register settings during initialization. Its behavior is fully characterized in Section 22.5 of the MC908AP64ACFBE electrical specifications.

Can the MC908AP64ACFBE operate from an internal RC oscillator without an external crystal?

Yes, the MC908AP64ACFBE includes an internal RC oscillator that provides a nominal 31.25 kHz clock source, usable as the base for the PLL or directly as the system clock. While less accurate than crystal-based timing (±5% typical), it eliminates external components for non-critical timing applications. The RC oscillator is factory-trimmed and can be calibrated further using the ICS module's auto-trim feature. All functional modes - including SCI communication and ADC sampling - remain operational with the internal RC source in the MC908AP64ACFBE.