NXP Semiconductors MC68340AB16E

Overview

MC68340AB16E from Freescale Semiconductor (formerly Motorola) is a 32-bit integrated processor with on-chip CPU32 core, DMA controller, serial module, dual timer modules, and system integration module - operating at 16 MHz, supporting 32-bit address/16-bit data bus, and featuring IEEE 1149.1 JTAG test access for embedded industrial control and communications equipment.

For engineers reviewing the MC68340AB16E datasheet, MC68340AB16E pinout, MC68340AB16E application, or MC68340AB16E equivalent, key selection considerations include its 16 MHz clock rating, 32-bit CPU32 instruction set compatibility with M68000 family, integrated peripheral register mapping, and support for external memory expansion via programmable chip selects and wait-state generation.

Technical Context

The MC68340AB16E implements the CPU32 core - a 32-bit superscalar derivative of the M68000 architecture - with full 32-bit addressing, 16-bit external data bus, and loop-mode instruction execution for deterministic real-time control. Its System Integration Module (SIM) integrates clock synthesis, interrupt handling, chip select generation, and periodic interrupt timer with software watchdog capability.

The on-chip DMA controller supports two independent channels with programmable priority and burst transfer modes, while the dual serial modules (UART/HDLC-compatible) and dual 16-bit timer modules provide synchronous/asynchronous communication and precise event timing - all mapped into a unified memory space with configurable base addresses.

Key Specifications

Pinout & Package

MC68340AB16E is housed in a 132-pin ceramic quad flat pack (CQFP) package with 0.65 mm lead pitch, designed for high-reliability industrial and telecom applications requiring thermal stability and long-term solder joint integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68340AB16E, MC68332ACPV16 offers reduced peripheral integration but simpler layout and lower cost for basic control, while MPC5604B provides higher performance and safety features at the expense of M68K software compatibility and increased design effort.

Availability

MC68340AB16E is available at Aetrix Electronics and suitable for industrial automation, telecom infrastructure, medical diagnostics, and avionics data acquisition requiring stable component supply and long-term obsolescence management.

Supply support for MC68340AB16E 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 devices - founded from Motorola's semiconductor division and focused on automotive, industrial, and networking markets.

The MC68340 belongs to the M68300 family of integrated processors targeting deterministic real-time embedded systems; it was engineered to consolidate CPU, DMA, serial, timer, and system control functions onto a single die for space-constrained, high-reliability applications.

FAQ

What is the maximum operating frequency of the MC68340AB16E?

The MC68340AB16E is rated for a maximum clock frequency of 16 MHz, as specified in its electrical characteristics and ordering information. This frequency determines the upper limit of CPU32 instruction throughput, peripheral timing margins, and bus cycle duration. Operation above 16 MHz is not guaranteed and may result in undefined behavior or timing violations. The MC68340AB16E uses an external crystal (EXTAL/XTAL) or clock source fed into its on-chip clock synthesizer to derive this system clock.

Does the MC68340AB16E support JTAG debugging?

Yes, the MC68340AB16E includes full IEEE 1149.1 Test Access Port (TAP) with dedicated TCK, TMS, TDI, and TDO pins, enabling boundary-scan testing and background debug mode (BDM) entry. This allows non-intrusive firmware debugging, register inspection, and memory access without halting real-time operation. The MC68340AB16E's BDM implementation is documented in Section 1.2.2 of the user's manual and requires compatible debugger hardware and software supporting M68K BDM protocols.

How many serial communication interfaces does the MC68340AB16E provide?

The MC68340AB16E integrates two independent serial modules (labeled A and B), each supporting UART-style asynchronous communication with RTS/CTS flow control, transmitter/receiver ready status signaling, and selectable clock sources including external SCLK or internal baud-rate generators. Both modules are fully programmable via memory-mapped registers and support standard framing (start/stop bits, parity) - making the MC68340AB16E suitable for dual-channel telemetry, modem interfacing, or redundant serial links in mission-critical systems.

What type of memory interface does the MC68340AB16E support?

The MC68340AB16E supports a 32-bit address / 16-bit data multiplexed external bus interface with programmable chip selects (CS0–CS3), wait-state generation, and dynamic bus sizing. It can interface directly with SRAM, EPROM, flash, and peripheral ASICs using either asynchronous or synchronous timing models. The System Integration Module (SIM) provides base address and address mask registers for each chip select, enabling flexible memory mapping - a key capability confirmed in Section 4.2.4 of the MC68340AB16E user's manual.

Is the MC68340AB16E pin-compatible with other members of the M68300 family?

No, the MC68340AB16E is not pin-compatible with other M68300 family members such as the MC68332 or MC68360 - despite sharing the CPU32 core and architectural similarities. Its 132-pin CQFP package, signal assignment (e.g., dual serial ports, dual timers, specific DMA and SIM signals), and pinout layout are unique to the MC68340AB16E and documented in Section 2 of the user's manual. Substituting other M68300 devices requires PCB redesign and firmware adaptation due to differences in peripheral integration and pin function allocation.