Section Ieee 1149.1 Test Access Port | Motorola MC68340 instruction

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SECTION 9 IEEE 1149.1 TEST ACCESS PORT

The MC68340 includes dedicated user-accessible test logic that is fully compatible with the IEEE 1149.1 Standard Test Access Port and Boundary Scan Architecture. Problems associated with testing high-density circuit boards have led to development of this proposed standard under the sponsorship of the Test Technology Committee of IEEE and the Joint Test Action Group (JTAG). The MC68340 implementation supports circuit-board test strategies based on this standard.

The test logic includes a test access port (TAP) consisting of four dedicated signal pins, a 16-state controller, an instruction register, and two test data registers. A boundary scan register links all device signal pins into a single shift register. The test logic, implemented using static logic design, is independent of the device system logic. The MC68340 implementation provides the following capabilities:

a.Perform boundary scan operations to test circuit-board electrical continuity

b.Sample the MC68340 system pins during operation and transparently shift out the result in the boundary scan register

c.Bypass the MC68340 for a given circuit-board test by effectively reducing the boundary scan register to a single bit

d.Disable the output drive to pins during circuit-board testing

NOTE

Certain precautions must be observed to ensure that the IEEE 1149.1 test logic does not interfere with nontest operation. See

9.6Non-IEEE 1149.1 Operation for details.

9.1OVERVIEW

NOTE

This description is not intended to be used without the supporting IEEE 1149.1 document.

The discussion includes those items required by the standard and provides additional information specific to the MC68340 implementation. For internal details and applications of the standard, refer to the IEEE 1149.1 document.

MOTOROLAMC68340 USER’S MANUAL9- 1

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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 Section Ieee 1149.1 Test Access Port, Non-IEEE 1149.1 Operation for details

Models: MC68340

Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.

SECTION 9

IEEE 1149.1 TEST ACCESS PORT

9.6Non-IEEE 1149.1 Operation for details.

9.1OVERVIEW

MC68340 specifications