NXP Semiconductors MC68LC302AF16CT

Overview

MC68LC302AF16CT 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 on-chip PLL supporting 32 kHz or 4 MHz crystals - designed for embedded communications and portable control systems.

For engineers reviewing the MC68LC302AF16CT datasheet, MC68LC302AF16CT pinout, MC68LC302AF16CT application, or MC68LC302AF16CT equivalent, key selection considerations include dual-SCC protocol support (HDLC/SDLC/UART/BISYNC), static-core low-power modes with wake-up via PIT or two dedicated pins, glueless memory interface using WEH/WEL/OE, and absence of SCC3 and external bus arbitration signals.

Technical Context

The MC68LC302AF16CT implements a static M68000 CPU core enabling full 16-bit operation with optional 8-bit boot mode, paired with an integrated System Integration Block (SIB) containing interrupt controller, PIO ports, and dual-port RAM. Its Communication Processor (CP) includes two independent full-duplex SCCs supporting HDLC, SDLC, UART, BISYNC, and autobaud - but omits SCC3 and associated BRG3.

It features a programmable PLL with MODCLK input for 32 kHz or 4 MHz crystal operation, new low-power standby modes activated via DISCPU or HALT, and wake-up capability from PIT interrupts or two configurable pins (PB8 and PB9). Memory interfacing uses WEH/WEL/OE instead of UDS/LDS/RW except in slave mode.

Key Specifications

Pinout & Package

MC68LC302AF16CT is packaged in a 100-pin Thin Quad Flat Pack (TQFP) with 0.5 mm pitch, measuring 14 mm × 14 mm × 1.4 mm - optimized for height-restricted applications including PCMCIA cards.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68302RC20 and MC68360VR66B, the MC68LC302AF16CT offers optimal balance of protocol flexibility, ultra-low height packaging, and sub-1 mA standby current - making it uniquely suited for space-constrained, battery-aware embedded communications where dual-SCC suffices and external bus arbitration is unnecessary.

Availability

MC68LC302AF16CT is available at Aetrix Electronics and suitable for industrial RTUs, PCMCIA modem cards, embedded fax controllers, and intelligent serial gateways requiring stable component supply across extended product lifecycles.

Supply support for MC68LC302AF16CT 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) was a leading designer of embedded processors, microcontrollers, and analog chips for automotive, industrial, and networking markets.

The MC68LC302 product line delivers cost-optimized, low-power variants of the MC68302 Integrated Multiprotocol Processor - targeting portable, space-constrained, and battery-operated communications equipment requiring dual-SCC protocol handling without full bus-mastering capability.

FAQ

What is the core architecture of the MC68LC302AF16CT?

The MC68LC302AF16CT features a static 68000 CPU core compatible with the M68000 instruction set, supporting both 8-bit and 16-bit data bus operation. It operates at 16.67 MHz with zero wait states under typical conditions and retains full software compatibility with existing M68000-based firmware. The static design enables true low-power standby modes - a key differentiator from the original MC68302 - and eliminates the need for external clock dividers or dynamic refresh logic.

Does the MC68LC302AF16CT support three serial communication controllers (SCCs)?

No, the MC68LC302AF16CT integrates only two full-duplex serial communication controllers (SCC1 and SCC2). SCC3 and its associated baud rate generator (BRG3) were removed to reduce pin count and cost compared to the MC68302. This makes the MC68LC302AF16CT ideal for applications requiring dual-protocol support (e.g., HDLC + UART) but not triple-channel redundancy. Pin assignments for TXD3/RXD3/RCLK3 do not exist on the 100-pin TQFP package.

What clock sources does the MC68LC302AF16CT support?

The MC68LC302AF16CT supports two crystal-based clock inputs via its on-chip PLL: a 32 kHz watch crystal for ultra-low-power timing or a 4 MHz oscillator for full-speed operation. The MODCLK pin (muxed with PA12) samples the selected source after reset. Unlike the MC68302, it does not require an external crystal oscillator circuit - the PLL generates the internal 16.67 MHz system clock directly, simplifying board layout and reducing BOM count.

Can the MC68LC302AF16CT operate in slave (CPU-disabled) mode?

Yes, the MC68LC302AF16CT supports slave mode via the DISCPU signal, allowing it to function as an intelligent peripheral under control of an external master CPU. In this mode, pins IPL2–0 become UDS/LDS/RW, restoring full 16-bit bus interface capability. The device retains full SCC, timer, and chip-select functionality - enabling DMA-driven serial offloading, timer-triggered events, and memory-mapped peripheral control without CPU intervention.

What package type and temperature range does the MC68LC302AF16CT use?

The MC68LC302AF16CT is supplied in a 100-pin Thin Quad Flat Pack (TQFP) package with 0.5 mm pitch and operates across the commercial temperature range of 0 °C to +70 °C. Its 14 mm × 14 mm × 1.4 mm profile meets PCMCIA Type II height constraints. The 'F' in the order code denotes the TQFP package, 'A' indicates 5 V operation, '16' specifies 16.67 MHz speed grade, and 'CT' confirms commercial temperature rating.