NXP Semiconductors MC68LC302CAF20CT

Overview

MC68LC302CAF20CT from Freescale is a low-power, static-core integrated multiprotocol processor based on the M68000 architecture, operating at 20 MHz with 5 V supply, housed in a 100-pin TQFP package. It integrates a dual-port RAM (1152 bytes), three timers (including watchdog and periodic interrupt timer), two full-duplex SCCs, four chip-select lines, and on-chip PLL supporting 32 kHz or 4 MHz crystals - deployed in PCMCIA cards and portable communication controllers.

For engineers reviewing the MC68LC302CAF20CT datasheet, MC68LC302CAF20CT pinout, MC68LC302CAF20CT application, or MC68LC302CAF20CT equivalent, key selection considerations include dual-SCC support, static core power efficiency, 100-pin TQFP footprint, absence of SCC3, and slave-mode bus arbitration capability.

Technical Context

The MC68LC302CAF20CT implements a static M68000 CPU core enabling zero-wait-state operation and deep low-power standby modes activated via HALT or DISCPU. Its System Integration Block (SIB) includes an interrupt controller with two operational modes, programmable address mapping for dual-port RAM and IMP registers, and glueless memory interface logic using WEH/WEL/OE instead of UDS/LDS/RW.

It features a dedicated Periodic Interrupt Timer (PIT) for wake-up scheduling and supports external wake-up on two pins. The on-chip PLL accepts either 32 kHz or 4 MHz crystal input, generating system clock without external oscillator - critical for minimizing board-level power and component count in portable designs.

Key Specifications

Pinout & Package

MC68LC302CAF20CT is packaged in a 100-pin Thin Quad Flat Pack (TQFP) with 0.5 mm lead pitch and 14 mm × 14 mm body size, optimized for space- and height-sensitive applications such as PCMCIA cards and handheld terminals.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68302RC20 and MC68332CAG16, the MC68LC302CAF20CT delivers optimal balance of protocol capability, power efficiency, and compact packaging for cost-sensitive, space-constrained embedded communications - without sacrificing dual-SCC functionality or deterministic low-power behavior.

Availability

MC68LC302CAF20CT is available at Aetrix Electronics and suitable for PCMCIA modem cards, industrial serial gateways, and portable data terminals requiring stable component supply, long-term lifecycle support, and RoHS-compliant manufacturing.

Supply support for MC68LC302CAF20CT 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, microcontrollers, and analog solutions for automotive, industrial, and networking markets.

The MC68LC302 product line targets cost-optimized, low-power communications processors - extending the MC68302 IMP family with static-core efficiency, reduced pin count, and TQFP packaging for portable and space-constrained systems.

FAQ

What is the primary function of the MC68LC302CAF20CT in embedded systems?

The MC68LC302CAF20CT serves as an integrated multiprotocol processor combining a static M68000 CPU core, dual serial communication controllers (SCCs), timers, dual-port RAM, and system control logic. It executes protocol stacks, manages peripheral I/O, and coordinates data flow in communications-centric embedded applications - all within a single 100-pin TQFP package. Its design eliminates external glue logic for memory interfacing and reduces power via static core and PLL-based clocking.

Does the MC68LC302CAF20CT support 32 kHz crystal operation?

Yes, the MC68LC302CAF20CT supports 32 kHz crystal operation through its on-chip PLL. The MODCLK pin is sampled at reset to configure the PLL for either 32 kHz or 4 MHz crystal input. This enables ultra-low-power standby modes while maintaining precise wake-up timing via the Periodic Interrupt Timer (PIT), making the MC68LC302CAF20CT especially suitable for battery-operated remote monitors and portable terminals.

How many serial communication controllers does the MC68LC302CAF20CT include, and what protocols do they support?

The MC68LC302CAF20CT includes two independent full-duplex Serial Communication Controllers (SCCs). Each supports High-Level Data Link Control (HDLC/SDLC), Universal Asynchronous Receiver Transmitter (UART), Binary Synchronous Communication (BISYNC), and transparent modes - including autobaud detection. Unlike the MC68302, it omits SCC3, reducing pin count while retaining dual-channel protocol flexibility for most point-to-point and multipoint communications tasks handled by the MC68LC302CAF20CT.

What package type and pin count does the MC68LC302CAF20CT use?

The MC68LC302CAF20CT uses a 100-pin Thin Quad Flat Pack (TQFP) package with 0.5 mm lead pitch and 14 mm × 14 mm body dimensions. This compact, low-profile package meets PCMCIA Type II height restrictions and reduces PCB area versus the 132-pin PGA variant of the MC68302. The pin layout reflects functional consolidation - for example, WEH/WEL/OE replace UDS/LDS/RW, and MODCLK replaces PA12 after reset - all documented in the official MC68LC302CAF20CT pin description table.

Can the MC68LC302CAF20CT operate in slave mode, and what is enabled in that configuration?

Yes, the MC68LC302CAF20CT supports slave mode via the DISCPU pin. In this mode, the CPU halts execution while the System Integration Block (SIB) and Communications Processor (CP) remain fully operational - allowing the MC68LC302CAF20CT to function as an intelligent peripheral driven by external DMA or host control. Bus signals BR, BG, and BGACK become available in slave mode, enabling external bus mastership without requiring redesign of existing MC68302-based systems relying on this architecture.