BDM Block Diagram | Motorola MC68340 specification

Inc.

Freescale Semiconductor, Inc.

memory access. Off-chip address comparators will not detect breakpoints on internal accesses unless show cycles are enabled. Breakpoints on prefetched instructions, which are flushed from the pipeline before execution, are not acknowledged, but operand breakpoints are always acknowledged. Acknowledged breakpoints can initiate either exception processing or BDM. See 5.5.2.6 Hardware Breakpoints for more information.

5.6.2 Background Debug Mode

BDM is an alternate CPU32 operating mode. During BDM, normal instruction execution is suspended, and special microcode performs debugging functions under external control. Figure 5-20 is a BDM block diagram.

BDM can be initiated in several ways—by externally generated breakpoints, by internal peripheral breakpoints, by the background instruction (BGND), or by catastrophic exception conditions. While in BDM, the CPU32 ceases to fetch instructions via the parallel bus and communicates with the development system via a dedicated, high-speed, SPI-type serial command interface.

Freescale Semiconductor,

MICROCODE

EXECUTION

UNIT

		SERIAL
		INTERFACE
	SEQUENCER
IRC	IRB	IR
BERR	BERR	BERR	BUS
			BUS
BKPT	BKPT	BKPT	CONTROL
BKPT	BKPT	BKPT

IPIPE/DSO

IFETCH/DSI

BKPT/DSCLK

DATA BUS

BERR

.FREEZE. ...

ADDRESS BUS

Figure 5-20. BDM Block Diagram

5.6.2.1ENABLING BDM. Accidentally entering BDM in a nondevelopment environment could lock up the CPU32 since the serial command interface would probably not be available. For this reason, BDM is enabled during reset via the BKPT signal.

MOTOROLAMC68340 USER’S MANUAL5- 65

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 BDM Block Diagram

Models: MC68340

Freescale Semiconductor, Inc.

5.6.2 Background Debug Mode

Freescale Semiconductor,

Figure 5-20. BDM Block Diagram

MC68340 specifications