Single-Address Write Timing External Burst

Freescale Semiconductor, Inc.

6.4.1.2SINGLE-ADDRESS WRITE. During the single-address destination (write) cycle, the DMA controls the transfer of data from a device to memory. The data is written to memory selected by the address specified in the destination address register (DAR), the

destination function codes in the FCR, and the size in the CCR. The destination (write) DMA bus cycle has timing identical to a write bus cycle. The DMA control signals (DACK≈ and DONE≈) are asserted in the destination (write) cycle. See Figures 6-7 and 6-8 for timing diagrams of single-address write for external burst and cycle steal modes.

	CPU CYCLE			DMA WRITE			DMA WRITE		CPU CYCLE
S0	S2	S4	S0	S2	S4	S0	S2	S4	S0
CLKOUT
A31–A0
FC3–FC0
SIZ1-SIZ0
AS
DS
R/W
D15–D0
DSACKx
DREQx
DONEx
(INPUT).
DACKx
DONEx
(OUTPUT)

NOTE:

1.Timing to generate more than one DMA request.

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

2.DREQx must be asserted while DACKx is asserted, and meet the setup and hold times for more than one DMA transfer to be recognized.

Figure 6-7. Single-Address Write Timing (External Burst)

6- 10

MC68340 USER’S MANUAL

MOTOROLA

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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 Single-Address Write Timing External Burst

Models: MC68340

Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.

(INPUT).

(OUTPUT)

Figure 6-7. Single-Address Write Timing (External Burst)

MC68340 specifications