Transmitter Timing Diagram | Motorola MC68340 manual

Freescale Semiconductor, Inc.

7.3.2.1TRANSMITTER. The transmitters are enabled through their respective command registers (CR) located within the serial module. The serial module signals the CPU32 when it is ready to accept a character by setting the transmitter-ready bit (TxRDY) in the channel's status register (SR). Functional timing information for the transmitter is shown in Figure 7-5.

The transmitter converts parallel data from the CPU32 to a serial bit stream on TxDx. It automatically sends a start bit followed by the programmed number of data bits, an optional parity bit, and the programmed number of stop bits. The least significant bit is sent first. Data is shifted from the transmitter output on the falling edge of the clock source.

C1 IN

TRANSMISSION

TxDx

BREAK

TRANSMITTER

ENABLED

TxRDY (SR2)

CS	W	W	W	W	W	W	W	W
	C1	C2	C3	START	C4	STOP	C5	C6
				BREAK		BREAK	NOT
							TRANSMITTED
CTS1
RTS 2		MANUALLY ASSERTED						MANUALLY
RTS 2		BY BIT- SET COMMAND						ASSERTED
		BY BIT- SET COMMAND						ASSERTED

NOTES:

1.TIMING SHOWN FOR MR2(4) = 1

2.TIMING SHOWN FOR MR2(5) = 1

3.CN = TRANSMIT CHARACTER

4.W = WRITE

Figure 7-5. Transmitter Timing Diagram

Following transmission of the stop bits, if a new character is not available in the transmitter holding register, the TxDx output remains high ('mark' condition), and the transmitter empty bit (TxEMP) in the SR is set. Transmission resumes and the TxEMP bit is cleared when the CPU32 loads a new character into the transmitter buffer (TB). If a disable command is sent to the transmitter, it continues operating until the character in the

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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 Transmitter Timing Diagram

Models: MC68340

Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.

Figure 7-5. Transmitter Timing Diagram

MC68340 specifications