Power Consumption Considerations, Cd-I, Cd-Rom

Freescale Semiconductor, Inc.

10.2.4Interfacing an 8-Bit Device to 16-Bit Memory Using Single- Address DMA Mode

One of the requirements of single-address mode is that the source and destination must be the same port size. However, the MC68340 can perform direct memory accesses in single-address mode between an 8-bit device and 16-bit memory. The port size must be specified as 8 bits, and some external logic is required as shown in Figure 10-14.

DEVICE	D15-D8

	R/W	T/R	B	MEMORY
	R/W	T/R		MEMORY
MC68340	A0		74F245
	A0		74F245
	SIZ1	OE
	SIZ1	OE	A
	SIZ0		A
	SIZ0		D7-D0

Figure 10-14. Circuitry for Interfacing 8-Bit Device to

16-Bit Memory in Single-Address DMA Mode

During even-byte accesses, the data is transferred directly on D15–D8. However, during odd-byte accesses, the data must be routed on D15–D8 for the 8-bit device and on D7– D0 for the 16-bit memory.

10.3 POWER CONSUMPTION CONSIDERATIONS

The MC68340 can be designed into low-power applications that involve high-performance processing capability (32-bits), high functional density, small size, portable capability, and battery operation.

The MC68340 fits into the following types of applications:

•	"Palmtop" Computers	•	Telephony
	— Stylus Input		— Cordless Phones
	— Voice Input		— Cellular Phones
	— Image Input	•	CD-I, CD-ROM
•	Transaction Tracking	•	Defense Industry
	— Car Rental		— Guidance Systems
	— Cargo		— Tracking Systems
	— Courier	•	Data Entry
	— Handheld	•	Instruments
•	Bar Code Scanners	•	Handheld Games
10-10		MC68340 USER’S MANUAL		MOTOROLA
		For More Information On This Product,
		Go to: www.freescale.com

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.

Motorola MC68340 manual Power Consumption Considerations, Cd-I, Cd-Rom

Models: MC68340

Freescale Semiconductor, Inc.

Figure 10-14. Circuitry for Interfacing 8-Bit Device to

16-Bit Memory in Single-Address DMA Mode

10.3 POWER CONSUMPTION CONSIDERATIONS

CD-I, CD-ROM

MC68340 specifications