NXP Semiconductors MC9RS08LA8CFT

Overview

MC9RS08LA8CFT from NXP Semiconductors (formerly Freescale) is an 8-bit RS08 core microcontroller in a 48-pin QFN package, operating at up to 10 MHz bus frequency across 2.7–5.5 V and –40°C to +85°C. It integrates 8 KB flash, 256-byte RAM, 6-channel 10-bit ADC, LCD driver supporting up to 8×21 segments, and single-wire background debug interface - deployed in low-power industrial control panels and embedded HMI systems.

For engineers reviewing the MC9RS08LA8CFT datasheet, MC9RS08LA8CFT pinout, MC9RS08LA8CFT application, or MC9RS08LA8CFT equivalent, key selection criteria include its QFN-48 thermal performance (θJA = 84°C/W on single-layer board), integrated LCD charge pump enabling 3 V/5 V glass compatibility, and stop-mode current of just 1.25 μA at 2.7 V - critical for battery-powered instrumentation and portable displays.

Technical Context

The MC9RS08LA8CFT implements an RS08 CPU core with subset of HC08 instruction set plus BGND, executing at up to 20 MHz core clock (10 MHz bus). Its clock system combines internal FLL (with trimmed DCO output of 16–20 MHz) and external crystal/resonator support (31.25 kHz–16 MHz), enabling flexible low-power timing across modes.

Peripherals are tightly coupled to power management: LCD controller remains functional in wait/stop modes; ADC operates fully in stop mode with 2.5 μs conversion; COP watchdog runs from dedicated 1 kHz internal source or bus clock; and KBI supports wake-up from stop with 100 ns pulse recognition.

Key Specifications

Pinout & Package

MC9RS08LA8CFT is housed in a 48-pin QFN package (Case 1975, 7 mm²) with exposed thermal pad. Pin assignments follow standard Freescale RS08 port mapping, with multiplexed functions including LCD segment/backplane drivers, ADC inputs, TPM channels, SCI/SPI interfaces, and keyboard interrupt pins.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC9RS08LA8CFT, the MC9RS08LA4CFT offers identical low-power LCD control and debug capability at lower memory cost, while the S9KEAZ128AMLH provides ARM-based headroom for feature-rich interfaces but demands architectural re-architecture and new qualification effort.

Availability

MC9RS08LA8CFT is available at Aetrix Electronics and suitable for industrial control panels, portable medical instruments, smart energy meter displays, and appliance user interfaces requiring stable component supply and long-term lifecycle support.

Supply support for MC9RS08LA8CFT 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, with deep heritage in microcontrollers dating back to Motorola and Freescale.

The MC9RS08LA8CFT belongs to the RS08 family - designed specifically for cost-sensitive, ultra-low-power embedded HMI and sensor-interface applications where small code size, integrated LCD support, and sub-μA stop current are critical.

FAQ

What is the maximum bus frequency supported by the MC9RS08LA8CFT?

The MC9RS08LA8CFT supports a maximum bus frequency of 10 MHz, achieved via its internal FLL with trimmed DCO output of up to 20 MHz (core clock). This frequency is guaranteed across the full operating range of 2.7–5.5 V and –40°C to +85°C, as specified in the Rev. 2 datasheet Section 3.8.1.

Does the MC9RS08LA8CFT support LCD operation in stop mode?

Yes, the MC9RS08LA8CFT LCD driver remains fully functional in stop mode, enabling continuous segment updates without CPU wake-up. This capability relies on the on-chip charge pump and independent LCD clock domain, delivering true ultra-low-power display operation - a key design feature confirmed in the "Peripherals" section of the MC9RS08LA8 datasheet.

What debug interface does the MC9RS08LA8CFT provide?

The MC9RS08LA8CFT features a single-wire background debug (BDC) interface using the PTC6 pin for BKGD function. It supports in-circuit programming, breakpoint setting, and real-time register inspection - all with minimal pin count and no external debug hardware required beyond a compatible BDM pod.

Can the MC9RS08LA8CFT operate from a 3 V battery without external regulators?

Yes, the MC9RS08LA8CFT operates over 2.7–5.5 V, making direct 3 V battery operation fully supported. Its stop-mode current drops to 1.31 μA at 3 V, and the integrated LCD charge pump eliminates need for external bias generation - enabling true single-supply, battery-powered HMI designs.

Is the MC9RS08LA8CFT pin-compatible with other RS08 family members in QFN-48?

The MC9RS08LA8CFT shares the same 48-pin QFN package (Case 1975) and pinout as MC9RS08LA4CFT and MC9RS08LA16CFT, as verified in Table 1 and Figure 2 of the MC9RS08LA8 Rev. 2 datasheet. Function mapping is identical across these variants, enabling hardware reuse across memory-tier SKUs.