NXP Semiconductors MC68HC908GR8CP

Overview

MC68HC908GR8CP from Freescale Semiconductor (formerly Motorola) is an 8-bit HCS08 microcontroller with 8 KB on-chip flash memory, 512 bytes RAM, and integrated peripherals including ADC, SCI, SPI, TIM, and KBI. It operates at up to 8 MHz internal bus speed, supports 3.0 V and 5.0 V supply, and targets cost-sensitive embedded control in industrial sensors and appliance subsystems.

For engineers reviewing the MC68HC908GR8CP datasheet, MC68HC908GR8CP pinout, MC68HC908GR8CP application, or MC68HC908GR8CP equivalent, key selection criteria include its 28-pin SOIC package, 8-channel 8-bit ADC, COP watchdog, low-voltage inhibit (LVI), and monitor ROM-based in-circuit programming capability.

Technical Context

The MC68HC908GR8CP implements the HCS08 CPU core with enhanced BCD arithmetic, 16-bit index registers, and a 16-level hardware stack. Its System Integration Module (SIM) integrates clock generation, reset control, interrupt management, and low-power modes (Wait/Stop).

Peripheral integration includes a 16-bit Timer Interface Module (TIM) with input capture/output compare, a Serial Communications Interface (SCI) supporting asynchronous full-duplex UART operation, and a Serial Peripheral Interface (SPI) with master/slave mode support - all directly memory-mapped and interrupt-capable.

Key Specifications

Pinout & Package

MC68HC908GR8CP is housed in a 28-pin Small Outline Integrated Circuit (SOIC) package (Case #751F), 300 mil body width, with 0.050" lead pitch and gull-wing leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC9RS08KA8CP and MC9S08QG8CDTE, the MC68HC908GR8CP offers balanced peripheral integration in a mature 28-pin SOIC package, making it optimal for space-constrained industrial controls where CAN is unnecessary and HCS08 ecosystem familiarity matters.

Availability

MC68HC908GR8CP is available at Aetrix Electronics and suitable for industrial sensor nodes, home appliance subsystems, and smart power outlet designs requiring stable component supply and long-term obsolescence management.

Supply support for MC68HC908GR8CP 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) was a leading designer of embedded controllers, analog, and RF solutions for automotive, industrial, and consumer markets.

The MC68HC908GR8CP belongs to the HCS08 microcontroller family, designed for cost-effective, low-power embedded control in appliances, sensors, and industrial equipment where flash programmability and mixed-signal integration are essential.

FAQ

What is the maximum operating frequency of the MC68HC908GR8CP?

The MC68HC908GR8CP supports a maximum bus frequency of 8 MHz, derived from its internal clock generator module (CGMC) with optional external crystal or RC oscillator input. This frequency governs instruction execution speed, ADC conversion rate, and peripheral timing - all specified under 3.0 V to 5.5 V supply and –40 °C to +85 °C operating conditions per the Rev. 4.0 datasheet.

Does the MC68HC908GR8CP support in-system programming?

Yes, the MC68HC908GR8CP includes a 256-byte Monitor ROM that enables in-system flash programming via its Serial Communications Interface (SCI) without requiring external hardware programmers. The MC68HC908GR8CP uses standard ASCII commands (e.g., READ, WRITE, RUN) sent over SCI to erase, program, and verify flash memory while the device remains soldered on the target board.

What low-power modes does the MC68HC908GR8CP provide?

The MC68HC908GR8CP supports two primary low-power modes: Wait Mode (CPU halted, peripherals active, wake via interrupt) and Stop Mode (all clocks stopped except LVI and RESET, wake via IRQ or RESET). Both modes reduce current consumption significantly - typical Stop Mode current is 1.0 µA at 3.0 V - making the MC68HC908GR8CP suitable for battery-backed or energy-harvesting applications.

How many ADC channels does the MC68HC908GR8CP have, and what is their resolution?

The MC68HC908GR8CP integrates an 8-bit successive-approximation analog-to-digital converter with eight input channels (AN0–AN7), accessible via Port E pins PTE0–PTE1 and dedicated ADC pins. Conversion time is programmable from 12 to 2048 bus cycles, and the ADC supports single-ended operation with internal reference or external VREFH/VREFL inputs as defined in Section 5 of the MC68HC908GR8CP datasheet.

Is the MC68HC908GR8CP pin-compatible with other members of the HC908 family?

No, the MC68HC908GR8CP is not fully pin-compatible with other HC908 variants such as the MC68HC908GR4 or MC68HC908JK1. While sharing the same 28-pin SOIC package outline, pin functions differ - for example, PTE0/PTE1 serve as ADC inputs on the MC68HC908GR8CP but as general-purpose I/O on the GR4. Migration requires verification of signal mapping, register initialization, and peripheral configuration in firmware.