NXP Semiconductors MC9RS08KA1CDBR

Overview

MC9RS08KA1CDBR from Freescale Semiconductor is an 8-bit RS08 microcontroller featuring a 20-MHz trimmable internal clock source, 1024 bytes of on-chip Flash EEPROM, 63 bytes of RAM, and integrated peripherals including an analog comparator (ACMP), 8-bit modulo timer (MTIM), and keyboard interrupt (KBI) module. It operates at up to 10 MHz bus frequency with 0.2% trim resolution and supports wake-up from stop mode via RTI, KBI, or ACMP - ideal for ultra-low-power sensor interface and simple control applications in space-constrained designs.

For engineers reviewing the MC9RS08KA1CDBR datasheet, MC9RS08KA1CDBR pinout, MC9RS08KA1CDBR application, or MC9RS08KA1CDBR equivalent, this device requires attention to its 6-pin DFN package constraints, single-byte addressing modes (tiny and short), COP watchdog independence from bus clock, and ACMP rail-to-rail operation with internal bandgap reference - all critical for reliable low-voltage embedded control.

Technical Context

The MC9RS08KA1CDBR implements the RS08 CPU core with simplified S08 instruction set extensions, including LDA/STA/CLR for short addressing ($0000–$001F) and ADD/SUB/INC/DEC for tiny addressing ($0000–$000F), enabling single-byte opcodes and reduced cycle counts. Its ICS supports FEI, FBI, and FBILP modes with factory-trimmed 20-MHz internal oscillator and ±2% deviation over voltage and temperature.

Memory architecture uses direct page access via paging window across full map; Flash is SuperFlash®-based with mass erase capability and security lock. Peripherals are register-mapped and accessible only in run or active background mode - ACMP and MTIM retain functionality in stop mode, while KBI supports edge/level-sensitive wake-up on three input pins in 6-pin configuration.

Key Specifications

Pinout & Package

MC9RS08KA1CDBR is housed in a 6-pin dual flat no-lead (DFN) package (case outline 98ASA00735D), measuring 2.0 × 2.0 × 0.55 mm with exposed thermal pad. This compact leadless package supports high-density PCB layouts and efficient thermal dissipation in battery-powered devices.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC9RS08KA2CDBR, the MC9RS08KA1CDBR saves die area and cost for minimal firmware; versus MC9S08QG8CDT, it trades interface capability and memory for ultra-low power and smallest footprint - making it optimal for cost-sensitive, space-constrained, battery-operated controls.

Availability

MC9RS08KA1CDBR is available at Aetrix Electronics and suitable for smart sensor nodes, portable medical devices, industrial control panels, and home appliance subsystems requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for MC9RS08KA1CDBR 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, automotive microcontrollers, and mixed-signal ICs, with deep expertise in low-power MCU architectures and industrial-grade reliability.

The MC9RS08KA1CDBR belongs to the RS08 microcontroller family - designed specifically for ultra-low-cost, ultra-low-power embedded control in space-constrained applications where minimal pin count, sub-µA stop current, and integrated analog functions are essential.

FAQ

What is the maximum operating frequency of the MC9RS08KA1CDBR bus clock?

The MC9RS08KA1CDBR supports a maximum bus clock frequency of 10 MHz, achieved when the internal clock source (ICS) operates in FEI or FBI mode with appropriate divider settings. This frequency determines instruction execution speed and peripheral timing margins; exceeding it may cause undefined behavior or failure to meet ACMP or timer specifications.

Does the MC9RS08KA1CDBR support in-circuit debugging, and how is it implemented?

Yes, the MC9RS08KA1CDBR supports single-wire background debug via the BKGD function on PTA3 pin. This requires no additional pins or hardware - the same pin serves as ACMP output during normal operation and debug interface during programming. The BDC module enables breakpoint setting and memory inspection without halting system clocks.

Can the analog comparator in the MC9RS08KA1CDBR operate while the MCU is in stop mode?

Yes, the ACMP in the MC9RS08KA1CDBR remains fully functional in stop mode, allowing continuous voltage monitoring with rail-to-rail input range and selectable internal 1.18 V bandgap reference. This enables wake-up on analog threshold crossing without waking the CPU - critical for battery longevity in sensor applications.

What packaging options are available for the MC9RS08KA1CDBR, and which one does the 'CDBR' suffix indicate?

The 'CDBR' suffix denotes the 6-pin DFN package (case outline 98ASA00735D), measuring 2.0 × 2.0 mm with wettable flank leads and exposed thermal pad. While the RS08KA1 family also offers 8-pin PDIP and SOIC variants, only the CDBR variant uses this compact leadless package optimized for high-density, low-profile designs.

How does the COP watchdog timer in the MC9RS08KA1CDBR differ from standard timeout-based watchdogs?

The COP watchdog in the MC9RS08KA1CDBR runs from a dedicated RC oscillator independent of the main bus clock - ensuring continued operation even if the ICS fails or system clock stops. This bus-independent design guarantees reliable reset on firmware hangs regardless of clock source integrity, meeting functional safety requirements in basic control systems.