NXP Semiconductors MC9RS08KA1CPC

Overview

MC9RS08KA1CPC 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), modulo timer (MTIM), and keyboard interrupt (KBI) module. It operates at up to 10 MHz bus frequency and supports Wait/Stop low-power modes with wake-up via RTI, KBI, or ACMP - ideal for cost-sensitive, space-constrained embedded control in consumer appliances and sensor interfaces.

For engineers reviewing the MC9RS08KA1CPC datasheet, MC9RS08KA1CPC pinout, MC9RS08KA1CPC application, or MC9RS08KA1CPC equivalent, key selection criteria include its 8-pin PDIP package, single-byte tiny/short addressing modes, COP watchdog with bus-independent clock, LVD reset capability, and background debug system support for in-circuit development.

Technical Context

The MC9RS08KA1CPC 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 efficient code density and reduced cycle count. Its ICS provides factory-trimmed 20-MHz internal reference with ±2% deviation over voltage and temperature, configurable for FEI/FBI/FBILP operational modes.

Peripherals are tightly coupled to low-power operation: the ACMP supports rail-to-rail input and internal bandgap reference comparison while active in Stop mode; the MTIM delivers 8-bit modulo timing with programmable prescaler; and the KBI supports edge- or level-sensitive wake-up on up to five pins depending on package variant.

Key Specifications

Pinout & Package

MC9RS08KA1CPC is supplied in an 8-pin plastic dual in-line package (PDIP), with 4 general-purpose I/O pins, 1 dedicated input, 1 dedicated output, and shared function pins for reset, background debug, and analog comparator output.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC9RS08KA2CPC, the MC9RS08KA1CPC trades Flash capacity for lower unit cost and smaller die size, while retaining identical low-power behavior and debug infrastructure; versus MC9S08QG4CDT, it offers lower BOM cost and simpler layout at the expense of communication interfaces and memory scalability.

Availability

MC9RS08KA1CPC is available at Aetrix Electronics and suitable for smart home sensors, LED lighting controllers, portable medical devices, and industrial panel meters requiring stable component supply and long-term manufacturability.

Supply support for MC9RS08KA1CPC 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 fabless semiconductor company specializing in microcontrollers, analog, and connectivity solutions for automotive, industrial, and consumer markets.

The MC9RS08KA1CPC belongs to the RS08 microcontroller family, designed specifically for ultra-low-cost, ultra-low-power embedded control in space- and budget-constrained applications where minimal external components and fast time-to-market are critical.

FAQ

What is the maximum operating frequency of the MC9RS08KA1CPC internal bus?

The MC9RS08KA1CPC supports a maximum bus frequency of 10 MHz, derived from its internal clock source (ICS) operating at up to 20 MHz with a 2× divider. This frequency is fully specified across the 2.7–5.5 V supply range and –40°C to +85°C temperature range per the Electrical Characteristics table in the datasheet. The MC9RS08KA1CPC achieves deterministic timing for real-time tasks such as LED PWM or sensor sampling without requiring external clock circuitry.

Does the MC9RS08KA1CPC support in-circuit debugging, and what interface is used?

Yes, the MC9RS08KA1CPC includes a Background Debug System (BDS) accessible via the BKGD pin (shared with PTA3). It uses a single-wire, half-duplex serial interface compatible with standard Freescale BDM tools. The MC9RS08KA1CPC supports breakpoint setting, memory read/write, and register inspection during active execution - enabling rapid firmware validation without requiring dedicated debug headers or JTAG pins.

How much Flash memory does the MC9RS08KA1CPC have, and is it reprogrammable in-system?

The MC9RS08KA1CPC contains 1024 bytes of on-chip Flash EEPROM that is fully reprogrammable in-system via the BKGD interface using standard Freescale programming algorithms. Flash supports byte/word writes and mass erase, with security features controlled by the FOPT register. This allows field firmware updates and eliminates the need for external programming hardware after initial board assembly - a key advantage of the MC9RS08KA1CPC in production environments.

Can the analog comparator in the MC9RS08KA1CPC operate while the device is in Stop mode?

Yes, the ACMP in the MC9RS08KA1CPC remains functional and can generate interrupts or wake the device from Stop mode. It supports full rail-to-rail input operation and optional comparison against an internal 1.22 V bandgap reference. This capability enables always-on threshold detection - for example, monitoring battery voltage or temperature sensor output - without consuming active-mode current, making it essential to the low-power design value of the MC9RS08KA1CPC.

What packages are offered for the MC9RS08KA1CPC, and which one is indicated by the 'CPC' suffix?

MC9RS08KA1CPC is offered in three package types: 6-pin DFN, 8-pin PDIP, and 8-pin SOIC. The 'CPC' suffix specifically denotes the 8-pin plastic dual in-line package (PDIP) variant. This through-hole package is optimized for prototyping, manual assembly, and legacy board designs where socket compatibility or ease of rework is prioritized over miniaturization - distinguishing it from the surface-mount DFN ('CFR') and SOIC ('CTS') variants of the same MC9RS08KA1 device.