Freescale Semiconductor, Inc.

Inc.

SECTION 10

APPLICATIONS

This section provides guidelines for using the MC68340. Minimum system-configuration requirements and memory interface information are discussed.

10.1 MINIMUM SYSTEM CONFIGURATION

One of the powerful features of the MC68340 is the small number of external components needed to create an entire system. The information contained in the following paragraphs details a simple high-performance MC68340 system (see Figure 10-1). This system configuration features the following hardware:

Freescale Semiconductor,

•Processor Clock Circuitry

•Reset Circuitry

•SRAM Interface

•ROM Interface

•Serial Interface

CLOCK

CIRCUITRY

SERIAL

INTERFACE

MC68340

SRAM

ROM

Figure 10-1. Minimum System Configuration Block Diagram

10.1.1 Processor Clock Circuitry

The MC68340 has an on-chip clock synthesizer that can operate from an on-chip phase- locked loop (PLL) and a voltage-controlled oscillator (VCO). The clock synthesizer uses an external crystal connected between the EXTAL and XTAL pins as a reference frequency source. Figure 10-2 shows a typical circuit using an inexpensive 32.768-kHz watch crystal. The 20-M resistor connected between the EXTAL and XTAL pins provides biasing for a faster oscillator startup time. The crystal manufacturer's documentation should be consulted for specific recommendations on external component values.

MOTOROLAMC68340 USER’S MANUAL10-1

For More Information On This Product,

Go to: www.freescale.com

Page 387 Page 389
Page 388
Image 388
Motorola MC68340 manual Minimum System Configuration, Processor Clock Circuitry
Page 387 Page 389

MC68340 specifications

The Motorola MC68340 is a highly integrated microprocessor that was introduced in the early 1990s. It belongs to the 68000 family of microprocessors and is designed to cater to the demands of embedded systems, particularly in telecommunications and networking applications. This chip represents a significant evolution in microprocessor technology by combining a microprocessor core with additional peripherals on a single chip, making it an attractive solution for engineers looking to design compact and efficient systems.

One of the key features of the MC68340 is its 32-bit architecture, which allows for significant processing power and data handling capabilities. This architecture enables the processor to handle larger data sizes and perform more complex calculations compared to its 16-bit predecessors. The MC68340 operates at clock speeds typically ranging from 16 MHz to 25 MHz. Its dual instruction pipeline enhances throughput, allowing for simultaneous instruction fetches and executions, which significantly boosts performance.

A notable characteristic of the MC68340 is the inclusion of integrated peripherals, which help reduce the overall component count in a system. Key integrated components include a memory management unit (MMU), a direct memory access (DMA) controller, and various communication interfaces such as serial ports. The memory management capabilities enhance the processor's ability to manage memory resources efficiently, enabling it to support multitasking environments commonly found in modern computing.

In terms of connectivity, the MC68340 features connections for both synchronous and asynchronous serial communication, making it well-suited for networking tasks. The processor supports a range of bus standards, including address and data buses, which facilitate seamless interaction with peripheral devices.

Another important aspect of the MC68340 is its flexibility. The processor supports multiple operating modes, including multiple CPU configurations and compatibility with the Motorola 68000 family, allowing for easier integration into existing systems.

Moreover, the MC68340 boasts low power consumption compared to many of its contemporaries, making it an excellent choice for battery-operated applications, enhancing its appeal in sectors like telecommunications, industrial control, and automotive systems. Its combination of performance, integration, versatility, and efficiency has secured the MC68340 a reputable position in the annals of embedded systems technology, proving to be a valuable asset for developers and engineers alike.
Top Page Image Contents