NXP Semiconductors KMC68LC302AF16CT

Overview

KMC68LC302AF16CT from Freescale is a low-cost integrated multiprotocol processor based on a static 68000 core, operating at 16.67 MHz with 5 V supply, housed in a 100-pin TQFP package. It integrates dual SCCs, three timers (including watchdog and PIT), 1152-byte dual-port RAM, four chip-select lines, and PLL support for 32 kHz or 4 MHz crystals - enabling use in PCMCIA cards and portable industrial controllers.

For engineers reviewing the KMC68LC302AF16CT datasheet, KMC68LC302AF16CT pinout, KMC68LC302AF16CT application, or KMC68LC302AF16CT equivalent, key selection considerations include dual-SCC protocol support (HDLC/UART/BISYNC), static-core low-power operation, glueless memory interface via WEH/WEL/OE, absence of SCC3 and external bus arbitration pins, and TQFP-100 footprint compatibility with height-constrained designs.

Technical Context

The KMC68LC302AF16CT implements a static M68000 CPU core with full 16-bit/8-bit system bus support and on-chip SIB (System Integration Block) containing interrupt controller, PIO ports, dual-port RAM, and three independent timers. Its CP (Communication Processor) block includes two full-duplex SCCs supporting HDLC, UART, BISYNC, and transparent modes with autobaud capability.

It features an on-chip PLL with 32 kHz or 4 MHz crystal input, new low-power standby modes with wake-up via PIT or two dedicated pins, and freeze control for debugging (PGA only). The device lacks SCC3, external bus arbitration signals (BR/BG/BGACK), and FC2–0 pins - distinguishing it from the MC68302 and confirming its role as a cost-optimized, space- and power-sensitive variant.

Key Specifications

Pinout & Package

Package: 100-pin Thin Quad Flat Pack (TQFP), lead-free, RoHS-compliant, body size 14 mm × 14 mm, 0.5 mm pitch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar integrated multiprotocol processor applications.

Compared with MC68302RC20 and MC68EC000FN16, the KMC68LC302AF16CT delivers optimized integration for dual-protocol edge nodes at lower cost and smaller footprint, trading off SCC3 and bus arbitration for reduced pin count and power - making it ideal where those features are unused.

Availability

KMC68LC302AF16CT is available at Aetrix Electronics and suitable for ISDN adapters, PCMCIA modems, industrial gateways, and portable data collectors requiring stable component supply and long-term lifecycle support.

Supply support for KMC68LC302AF16CT 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) was a leading designer of embedded processors, analog, and mixed-signal ICs for automotive, industrial, and networking markets.

The MC68LC302 product line targets cost-sensitive, space-constrained embedded systems requiring integrated serial protocol handling, low-power operation, and minimal external logic - especially in portable and PCMCIA form factors.

FAQ

What is the core architecture of the KMC68LC302AF16CT?

The KMC68LC302AF16CT uses a static version of the Motorola 68000 16/32-bit CPU core, supporting both 8-bit and 16-bit data bus operation. Unlike the dynamic 68000, this static implementation allows full stop-mode power-down and eliminates the need for external refresh circuitry - a key enabler for battery-powered applications. The core executes the full M68000 instruction set and interfaces directly with the on-chip System Integration Block (SIB) and Communication Processor (CP).

Does the KMC68LC302AF16CT support 3.3 V operation?

No, the KMC68LC302AF16CT is a 5 V-only device. Its ordering code "AF16CT" indicates 5 V supply, 16.67 MHz operation, and commercial temperature range (0°C to 70°C). While Freescale offered 3.3 V variants (e.g., MC68LC302PU16V), the KMC68LC302AF16CT specifically requires 5 V ±5% and is not tolerant of 3.3 V supply rails. Using it with 3.3 V will result in functional failure or damage.

How many serial communication controllers does the KMC68LC302AF16CT include?

The KMC68LC302AF16CT includes exactly two independent full-duplex Serial Communication Controllers (SCCs), designated SCC1 and SCC2. Each supports HDLC/SDLC, UART, BISYNC, and transparent modes with autobaud capability. SCC3 - present in the MC68302 - is explicitly removed in the KMC68LC302AF16CT to reduce pin count and cost, as confirmed in Freescale's official addendum documentation.

Can the KMC68LC302AF16CT operate in slave mode with external bus control?

Yes, the KMC68LC302AF16CT supports CPU-disabled (slave) mode via the DISCPU pin, allowing external masters to control the bus using HALT and the remapped IPL pins (UDS/LDS/RW become available in this mode). However, unlike the MC68302, it lacks dedicated BR/BG/BGACK arbitration pins - so external bus takeover requires HALT-based coordination rather than full arbitration. This mode retains full SCC, timer, and chip-select functionality while the CPU is inactive.

What clock sources does the on-chip PLL in the KMC68LC302AF16CT accept?

The KMC68LC302AF16CT's on-chip PLL accepts either a 32 kHz tuning-fork crystal or a 4 MHz fundamental-mode crystal connected across XTAL and EXTAL pins. The MODCLK pin (muxed with PA12) samples the crystal type after reset to configure PLL multiplication. This dual-frequency option enables flexible trade-offs between ultra-low-power sleep timing (32 kHz) and higher-speed system clocks (e.g., 16.67 MHz), all without external clock generators - a feature confirmed in the MC68LC302 Product Brief and Addendum.