NXP Semiconductors MC9RS08LA8CLF

Overview

MC9RS08LA8CLF from NXP Semiconductors (formerly Freescale) is an 8-bit RS08 core microcontroller with 8 KB flash, 256-byte RAM, integrated LCD driver (up to 8×21 segments), 6-channel 10-bit ADC, and single-wire background debug interface - designed for low-power embedded control in space-constrained industrial and consumer displays. It operates from 2.7 V to 5.5 V at up to 10 MHz bus frequency across –40°C to +85°C.

For engineers reviewing the MC9RS08LA8CLF datasheet, MC9RS08LA8CLF pinout, MC9RS08LA8CLF application, or MC9RS08LA8CLF equivalent, key selection criteria include QFN-48 package compatibility, LCD segment drive capability without external charge pump, stop-mode current of 1.25 μA at 2.7 V, and integrated 1 kHz RTI for ultra-low-power wake-up timing.

Technical Context

The MC9RS08LA8CLF implements an RS08 CPU core - a subset of the HC08 instruction set augmented with BGND - executing instructions at up to 20 MHz core clock (10 MHz bus clock). Its internal clock source (ICS) uses a frequency-locked loop (FLL) locked to either an internal trimmed reference (31.25–39.0625 kHz) or external crystal/resonator (31.25 kHz–16 MHz), enabling stable bus frequencies up to 10 MHz without external oscillator components.

System-level timing control includes a real-time interrupt (RTI) module with selectable 1 kHz internal clock source, a 2-channel 16-bit timer/pulse-width modulator (TPM), and an 8-bit modulo timer (MTIM). The analog subsystem integrates a 6-channel 10-bit ADC with 2.5 μs conversion time, internal bandgap reference, temperature sensor (1.7 mV/°C), and operation down to 2.7 V - all functional in stop mode with only 121.22 μA adder current.

Key Specifications

Pinout & Package

MC9RS08LA8CLF is housed in a 48-pin QFN package (Case 1975, 7 mm² footprint) with exposed thermal pad. Pin assignments support multiplexed functions including LCD segment/backplane drivers, SPI/SCI/TPM peripherals, and keyboard interrupt inputs - all configurable via register settings.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit microcontroller applications.

Compared with MC9RS08LA4CLF, the MC9RS08LA8CLF provides double flash/RAM for richer UI logic and data logging; compared with S9KEAZ128AMLH, it offers pin-compatible legacy support and lower power in stop mode (1.25 μA vs. ~2.5 μA), making it optimal for cost-sensitive, battery-constrained display controllers.

Availability

MC9RS08LA8CLF is available at Aetrix Electronics and suitable for industrial panel displays, smart thermostats, portable medical monitors, and appliance control panels requiring stable component supply and long-term lifecycle support.

Supply support for MC9RS08LA8CLF 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 applications - formed through the acquisition of Freescale Semiconductor in 2015.

The MC9RS08LA8CLF belongs to the RS08 family of ultra-low-power 8-bit MCUs designed specifically for cost-sensitive, space-constrained embedded displays and human-interface applications requiring integrated LCD driving and minimal external components.

FAQ

What is the maximum bus frequency supported by the MC9RS08LA8CLF?

The MC9RS08LA8CLF supports a maximum bus frequency of 10 MHz, achieved via its internal clock source (ICS) with frequency-locked loop (FLL) - enabling deterministic real-time execution for display refresh, keypad scanning, and sensor polling. This frequency is guaranteed across the full operating voltage range (2.7 V to 5.5 V) and temperature range (–40°C to +85°C), as specified in the Rev. 2 datasheet Section 3.8.1.

Does the MC9RS08LA8CLF support LCD operation in stop mode?

Yes, the MC9RS08LA8CLF supports full LCD operation in stop mode, including segment and backplane drive functionality - critical for ultra-low-power display hold. Its integrated charge pump enables compatibility with both 3 V and 5 V LCD glass without external components, and the LCD module remains fully functional while consuming only the base stop-mode current (1.25 μA at 2.7 V), as documented in the "Peripherals" section of the MC9RS08LA8 datasheet Rev. 2.

What debug interface does the MC9RS08LA8CLF use?

The MC9RS08LA8CLF uses a single-wire background debug (BKGD) interface routed to PTC6, supporting full in-circuit debugging including breakpoint setting and memory inspection. This interface requires only one GPIO and an external pull-up resistor - eliminating the need for dedicated debug headers or multi-pin SWD/JTAG connectors. The MC9RS08LA8CLF's BKGD implementation is defined in the Reference Manual (MC9RS08LA8RM) and is compatible with standard Freescale/NXP BDM tools.

Can the MC9RS08LA8CLF's ADC operate during stop mode?

Yes, the MC9RS08LA8CLF's 6-channel 10-bit ADC can operate during stop mode, with a typical adder current of 121.22 μA at 2.7 V. This capability enables low-power sensor measurements - such as temperature or battery voltage - without waking the CPU core. The ADC retains full functionality including internal bandgap reference, automatic compare, and temperature sensor (1.7 mV/°C), as confirmed in Section 3.11 of the MC9RS08LA8 Rev. 2 datasheet.

What is the purpose of the VCAP1 and VCAP2 pins on the MC9RS08LA8CLF?

The VCAP1 and VCAP2 pins on the MC9RS08LA8CLF connect to external 100 nF ceramic decoupling capacitors that stabilize the internal voltage regulator - essential for reliable operation of the RS08 core and analog peripherals. These pins must be placed as close as possible to the MCU package per Freescale's layout guidelines (EB806), and omission or undersizing causes increased noise, ADC inaccuracy, or erratic reset behavior. Both capacitors are required for all operating conditions, as specified in the "Electrical Characteristics" section of the MC9RS08LA8 Rev. 2 datasheet.