NXP Semiconductors M68LC302CAF20VCT

Overview

M68LC302CAF20VCT from Freescale is a low-cost integrated multiprotocol processor featuring a static 68000 core, dual serial communication controllers (SCCs), three timers including watchdog and periodic interrupt timer (PIT), 1152-byte on-chip dual-port RAM, and 4 programmable chip-select lines - deployed in portable communications, PCMCIA cards, and low-power embedded control systems.

For engineers reviewing the M68LC302CAF20VCT datasheet, M68LC302CAF20VCT pinout, M68LC302CAF20VCT application, or M68LC302CAF20VCT equivalent, key selection considerations include its 20 MHz operation at 3.3 V, TQFP-100 package with height-constrained footprint, absence of SCC3, reduced bus arbitration capability, and PLL support for 32 kHz or 4 MHz crystals.

Technical Context

The M68LC302CAF20VCT implements a static 68000 CPU core supporting both 8-bit and 16-bit system buses, with glueless interface to EPROM, SRAM, Flash, and EEPROM via WEH/WEL/OE control signals and four chip-selects with wait-state logic. Its System Integration Block (SIB) integrates an interrupt controller with two operational modes, parallel I/O ports with interrupt capability, and programmable address mapping for dual-port RAM and IMP registers.

It includes a Communication Processor (CP) with two full-duplex SCCs supporting HDLC/SDLC, UART, BISYNC, transparent modes, and autobaud; a new Periodic Interrupt Timer (PIT); low-power standby modes with wake-up from two pins or PIT; and on-chip PLL enabling clock generation from 32 kHz or 4 MHz crystals - while omitting SCC3, external bus arbitration pins (BG/BGACK/BR), and FC2–0/IAC/FRZ/AVEC signals present in the MC68302.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68302RC20 and MC68360VR33B, the M68LC302CAF20VCT delivers optimized value for dual-serial, low-power, space-constrained applications - trading SCC3 and bus arbitration for reduced size, lower voltage operation, and integrated PLL-based clocking without sacrificing 68K software compatibility or real-time determinism.

Availability

M68LC302CAF20VCT is available at Aetrix Electronics and suitable for handheld data terminals, PCMCIA modem cards, and industrial remote telemetry units requiring stable component supply, long-term lifecycle support, and RoHS-compliant manufacturing.

Supply support for M68LC302CAF20VCT 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 targets cost- and power-sensitive embedded control applications requiring multiprotocol serial connectivity, deterministic real-time response, and compact packaging - extending the legacy 68K architecture into portable and space-constrained systems.

FAQ

What is the operating voltage range for the M68LC302CAF20VCT?

The M68LC302CAF20VCT operates at 3.3 V nominal with ±0.3 V tolerance. It is not rated for 5 V operation - unlike earlier MC68LC302 variants with 'PU' or 'RC' suffixes. This 3.3 V design reduces dynamic power consumption and enables direct interfacing with modern low-voltage peripherals without level-shifting circuitry. The M68LC302CAF20VCT must be powered from a regulated 3.3 V supply meeting Freescale's recommended decoupling and sequencing requirements per the MC68LC302 datasheet.

Does the M68LC302CAF20VCT support all three serial communication controllers like the MC68302?

No, the M68LC302CAF20VCT omits SCC3 and its associated baud rate generator (BRG3), pins TXD3/RXD3/RCLK3, and SCP functionality. It retains only SCC1 and SCC2 - each fully functional with HDLC/SDLC, UART, BISYNC, and autobaud support. This reduction enabled the pin count decrease from 132 to 100 and contributed to lower cost and power. Engineers using the M68LC302CAF20VCT must verify that their application requires only two serial channels before migration from the MC68302.

What package type and dimensions does the M68LC302CAF20VCT use?

The M68LC302CAF20VCT uses a 100-pin Thin Quad Flat Pack (TQFP) package measuring 14 mm × 14 mm with 0.5 mm lead pitch. Its maximum height is 1.4 mm - making it suitable for PCMCIA Type II (5.5 mm height limit) and other height-restricted applications. This contrasts with the MC68302's 132-pin PGA package, which exceeds 4 mm in height and requires socketing or specialized PCB layout. The TQFP-100 also supports standard reflow soldering processes.

Can the M68LC302CAF20VCT operate from a 32 kHz crystal, and what is the role of the XFC pin?

Yes, the M68LC302CAF20VCT supports 32 kHz crystal input via XTAL/EXTAL pins, with the on-chip PLL generating the 20 MHz system clock. The XFC pin configures PLL feedback division ratio - tied high or low at reset to select between 32 kHz or 4 MHz crystal modes. This dual-crystal option allows designers to minimize power in sleep states (using 32 kHz) while maintaining full-speed operation when active. The M68LC302CAF20VCT's PLL eliminates need for external clock generators and reduces overall system BOM count.

Is the M68LC302CAF20VCT pin-compatible with any other MC68LC302 variants?

The M68LC302CAF20VCT shares the same 100-pin TQFP footprint and signal mapping as other 'PU' and 'CPU' suffix variants (e.g., MC68LC302PU20, MC68LC302CPU16V), but differs in voltage rating (3.3 V only) and temperature grade (–40°C to +85°C). It is not pin-compatible with PGA variants (e.g., MC68LC302RC20) due to different pin count and signal assignment. Layout reuse is possible across TQFP variants, but power supply and thermal design must reflect the 3.3 V/extended temperature requirements of the M68LC302CAF20VCT.