NXP Semiconductors MC68908GR16VFJE

Overview

MC68908GR16VFJE from Freescale Semiconductor is an 8-bit HCS08-core microcontroller with 16 KB on-chip Flash memory, 512 B RAM, and integrated peripherals including ADC, SPI, ESCI, TIM, KBI, and CGM with PLL-based clock generation. It operates at up to 8 MHz bus frequency, supports 3.3 V or 5.0 V supply, and targets embedded control in industrial sensors and motor interface modules.

For engineers reviewing the MC68908GR16VFJE datasheet, MC68908GR16VFJE pinout, MC68908GR16VFJE application, or MC68908GR16VFJE equivalent, key selection criteria include its 48-pin LQFP package, 8-channel 10-bit ADC with internal reference, programmable PLL for flexible clock synthesis, and COP watchdog with selectable timeout periods.

Technical Context

The MC68908GR16VFJE implements the HCS08 CPU core with enhanced instruction set, 16-bit index register, and stack pointer. Its Clock Generator Module integrates a crystal oscillator, PLL with programmable multiplier (×1 to ×32), and base clock selector supporting multiple clock sources including external crystal, RC, or internal reference.

The device includes a 10-bit successive-approximation ADC with 8 input channels, configurable sample time, and left/right-justified result storage. The Enhanced Serial Communications Interface (ESCI) supports asynchronous full-duplex UART operation with programmable baud rate, parity, and stop bits - all synchronized to CGMXCLK or bus clock.

Key Specifications

Pinout & Package

MC68908GR16VFJE is housed in a 48-pin LQFP (7 mm × 7 mm, 0.5 mm pitch) package with exposed thermal pad. Pin functions are defined per Chapter 1.4 and 1.5 of the Rev. 5.0 datasheet, including dedicated oscillator, reset, interrupt, ADC, and serial interface signals.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68908GR16VFJE, MC9RS08KA8CFMR trades clock flexibility and I/O for lower cost and footprint, while S9KEAZ128AMLH provides architectural modernization at the expense of compatibility and design continuity.

Availability

MC68908GR16VFJE is available at Aetrix Electronics and suitable for industrial sensor nodes, motor interface modules, HVAC actuators, and legacy equipment retrofit programs requiring stable component supply and long-term manufacturability.

Supply support for MC68908GR16VFJE 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 mixed-signal microcontrollers for automotive and industrial markets, emphasizing robustness, low-power operation, and integrated analog peripherals.

The MC68HC908GR16 family was designed for cost-effective, real-time embedded control in resource-constrained environments - delivering Flash-based programmability, on-chip clock synthesis, and peripheral integration without external support ICs.

FAQ

What is the maximum operating frequency of the MC68908GR16VFJE bus clock?

The MC68908GR16VFJE supports a maximum bus clock frequency of 8 MHz. This is derived from the PLL output (CGMXCLK), which can be programmed up to 20 MHz, but the CPU bus clock is divided by a configurable prescaler. The datasheet specifies 8 MHz as the rated maximum for reliable operation across voltage and temperature ranges.

Does the MC68908GR16VFJE support in-system programming (ISP)?

Yes, the MC68908GR16VFJE supports in-system programming via its on-chip background debug interface (BDM). Flash memory can be reprogrammed without removing the device from the circuit, using standard Freescale BDM tools and compatible third-party programmers. The MC68908GR16VFJE Flash architecture includes mass and page erase commands accessible through the FLASH control register.

Can the ADC on the MC68908GR16VFJE operate during Stop mode?

No, the ADC cannot operate during Stop mode on the MC68908GR16VFJE. In Stop mode, the CGM and most peripherals are disabled to minimize current draw. The ADC requires active clocking (from CGMXCLK or bus clock) and analog power (VDDA/VSSA), both of which are gated in Stop mode. Conversion is only supported in Normal and Wait modes.

What packaging and RoHS status applies to the MC68908GR16VFJE?

The MC68908GR16VFJE is supplied in a 48-pin LQFP package (7 mm × 7 mm, 0.5 mm pitch) with exposed thermal pad. It is RoHS-compliant and lead-free, meeting JEDEC J-STD-020 moisture sensitivity level MSL-3. The "VFJE" suffix denotes this specific RoHS-compliant LQFP variant per Freescale's ordering information in Chapter 21 of the datasheet.

How is the PLL locked and monitored on the MC68908GR16VFJE?

The MC68908GR16VFJE PLL lock status is reported via the LOCK bit (bit 7) in the PLL Control Register (PLLCR). Software reads this bit after enabling the PLL and waiting for acquisition time (typically 3–5 ms). The CGMINT interrupt can also be configured to assert on lock/unlock events. The PLL bandwidth and multiplier are set independently via dedicated registers to ensure stable lock under varying temperature and supply conditions.