Motorola MC68340 manual Long-Word and Word Read and Write Timing-16-Bit Port

Models: MC68340

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Freescale Semiconductor, Inc...

 

 

 

Freescale Semiconductor, Inc.

 

 

 

 

S0

S2

S4

S0

S2

S4

S0

S2

S4

S0

S2

S4

S0

S2

S4

S0

S2

S4

CLKOUT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

A31–A0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

FC3–FC0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R/W

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

AS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SIZ0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4 BYTES

 

2 BYTES

 

2 BYTES

 

4 BYTES

 

2 BYTES

 

2 BYTES

SIZ1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DSACK0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DSACK1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D15–D8

 

OP0

 

 

OP2

 

 

OP0

 

 

OP0

 

 

OP2

 

OP0

D7–D0

 

OP1

 

 

OP3

 

 

OP1

 

 

OP1

 

 

OP3

 

OP1

 

 

LONG WORD READ

 

 

 

 

 

 

 

 

 

 

 

WORD

 

 

 

 

WORD READ

 

LONG WORD WRITE TO

 

 

WRITE TO

 

 

 

FROM 16-BIT BUS

 

FROM 16-BIT BUS

 

 

16-BIT BUS

 

 

 

16-BIT BUS

 

Figure 3-5. Long-Word and Word Read and Write Timing—16-Bit Port

The MC68340 drives the address bus with the desired address and drives the SIZx pins to indicate a long-word operand. For a read operation, the slave responds by placing the two most significant bytes of the operand on bits 15–0 of the data bus and asserting DSACK1 to indicate a 16-bit port. The MC68340 reads the two most significant bytes of the operand (bytes 0 and 1) from bits 15–0. The MC68340 then decrements the transfer size counter by 2, increments the address by 2, initiates a new cycle, and reads bytes 2 and 3 of the operand from bits 15–0 of the data bus.

For a write operation, the MC68340 drives the two most significant bytes of the operand on bits 15–0 of the data bus. The slave device then reads the two most significant bytes of the operand (bytes 0 and 1) from bits 15–0 of the data bus and asserts DSACK1 to indicate reception and a 16-bit port. The MC68340 then decrements the transfer size counter by 2, increments the address by 2, and writes bytes 2 and 3 of the operand to bits 15–0 of the data bus.

MOTOROLA

MC68340 USER’S MANUAL

3- 13

For More Information On This Product,

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Motorola MC68340 manual Long-Word and Word Read and Write Timing-16-Bit Port

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.