NXP Semiconductors M68LC302CPU16VCT

Overview

M68LC302CPU16VCT from Freescale is a low-power, static 68000-core integrated multiprotocol processor with dual serial communication controllers (SCCs), 1152-byte on-chip dual-port RAM, periodic interrupt timer (PIT), and 32 kHz/4 MHz PLL clock generation. It operates at 16.67 MHz, supports 3.3 V supply, and targets space- and power-constrained embedded systems such as PCMCIA cards and portable industrial controllers.

For engineers reviewing the M68LC302CPU16VCT datasheet, M68LC302CPU16VCT pinout, M68LC302CPU16VCT application, or M68LC302CPU16VCT equivalent, key selection considerations include its 100-pin TQFP package, absence of SCC3, glueless memory interface via WEH/WEL/OE, slave-mode bus control, and wake-up capability from PIT or two dedicated pins.

Technical Context

The M68LC302CPU16VCT integrates a static 68000 CPU core with a System Integration Block (SIB) containing interrupt controller, parallel I/O ports, four chip-select lines with wait-state logic, and three timers-including a watchdog and a programmable periodic interrupt timer (PIT). Its Communication Processor (CP) implements two full-duplex SCCs supporting HDLC/SDLC, UART, BISYNC, and transparent modes with autobaud.

Unlike the MC68302, it removes SCC3, external bus arbitration signals (BR/BG/BGACK), UDS/LDS/RW (except in slave mode), and FC/IAC/FRZ/AVEC pins-reducing pin count to 100 while adding PLL support pins (XFC, VCCSYN, GNDSYN) and MODCLK for low-power operation. Memory interface uses WEH/WEL/OE instead of standard bus control signals.

Key Specifications

Pinout & Package

Package: 100-pin Thin Quad Flat Pack (TQFP), lead-free, RoHS-compliant, 14 mm × 14 mm body, 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 MPC823EZQ266D, the M68LC302CPU16VCT delivers optimal balance of protocol flexibility, ultra-low-power operation, and compact packaging - making it uniquely suited for cost-sensitive, battery-operated, or space-limited embedded controllers where dual SCCs and deterministic low-power scheduling are primary requirements.

Availability

M68LC302CPU16VCT is available at Aetrix Electronics and suitable for industrial telemetry gateways, PCMCIA modem cards, and low-power data loggers requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for M68LC302CPU16VCT 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, analog, and mixed-signal ICs for automotive, industrial, and networking markets.

The MC68LC302 product line was developed to deliver cost-optimized, low-power variants of the MC68302 IMP family - specifically targeting portable, space-constrained, and battery-operated embedded systems requiring dual serial protocol support without full bus-mastering capability.

FAQ

What is the operating voltage range for the M68LC302CPU16VCT?

The M68LC302CPU16VCT operates at a nominal supply voltage of 3.3 V with a tolerance of ±0.3 V (3.0 V to 3.6 V). This voltage level is strictly defined in the Freescale MC68LC302 datasheet and enables compatibility with modern low-voltage memory and peripheral ICs. Operation outside this range may cause undefined behavior or permanent damage. The M68LC302CPU16VCT does not support 5 V operation - unlike earlier MC68302 variants.

Does the M68LC302CPU16VCT support all three serial communication controllers (SCCs) found in the MC68302?

No, the M68LC302CPU16VCT omits SCC3 and its associated baud rate generator (BRG3), pins (TXD3/RXD3/RCLK3), and control logic. It retains only SCC1 and SCC2, each supporting HDLC/SDLC, UART, BISYNC, and transparent modes with autobaud. This reduction enables the 100-pin TQFP package and aligns with applications that require dual-channel serial protocol handling but not triple redundancy or expansion.

Can the M68LC302CPU16VCT be used in slave mode with an external bus master?

Yes, the M68LC302CPU16VCT supports slave mode via the DISCPU pin. When asserted, it disables the internal CPU and releases the address/data bus, allowing an external master to control memory-mapped peripherals including the dual-port RAM, SCCs, timers, and chip selects. In this mode, UDS/LDS/RW signals become available as IPL2–IPL0, enabling full peripheral access without CPU interference.

What clock sources does the on-chip PLL in the M68LC302CPU16VCT accept?

The M68LC302CPU16VCT on-chip PLL accepts either a 32 kHz crystal (for ultra-low-power sleep modes) or a 4 MHz crystal (for higher-performance active operation). The MODCLK pin samples the selected source after reset and configures the PLL accordingly. This dual-input capability allows designers to optimize system power budget and timing precision without external clock synthesizers.

Is the M68LC302CPU16VCT pin-compatible with any other Freescale processor packages?

No, the M68LC302CPU16VCT is not pin-compatible with the 132-pin MC68302 PGA or any other Freescale processor. Its 100-pin TQFP footprint, redefined bus control signals (WEH/WEL/OE instead of UDS/LDS/RW), and relocated peripheral pins (e.g., SCP muxed onto PA8–PA10) make it mechanically and electrically distinct. Migration from MC68302 requires PCB redesign and firmware adaptation.