Fast Termination Option Cycle Steal | Motorola MC68340 instruction

Freescale Semiconductor, Inc.

	Freescale Semiconductor, Inc.
	CPU CYCLE			DMA READ		CPU CYCLE		.DMA............... . READ
S0	S2	S4	S0	S4	S0	S2	S4	S0	S2
CLKOUT
A31–A0
FC3–FC0
SIZ1–SIZ0
AS
DS
R/W
D15–D0
DSACKx
DREQx
DACKx
DONEx
(OUTPUT)

NOTE:

1.To cause another DMA transfer, DREQx is asserted after DACKx is asserted and before DACKx is negated.

2.DACKx and DONEx (DMA control signals) are asserted in the source (read) DMA cycle.

Figure 6-13. Fast Termination Option (Cycle Steal)

If the fast termination option is used with external burst request mode (Figure 6-14), an extra DMA cycle may result on every burst transfer. Normally, DREQ≈ is negated when DACK≈ is returned. In the burst mode with fast termination selected, a new cycle starts even if DREQ≈ is negated simultaneously with DACK≈ assertion.

MOTOROLAMC68340 USER’S MANUAL6- 21

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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 Fast Termination Option Cycle Steal

Models: MC68340

Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.

Figure 6-13. Fast Termination Option (Cycle Steal)

MOTOROLAMC68340 USER’S MANUAL6- 21

MC68340 specifications