Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.

Table 8-1. OCx Encoding

OC1 OC0 TOUTx

0 0Hi-Z

0 10

1 00

1 11

A read of the SR while in this mode always shows the TO, TC, and COM bits cleared, and the PO bits as $FF. The SR OUT bit always indicates the level on the TOUTx pin.

8.3.9 Bus Operation

The following paragraphs describe the operation of the IMB during read, write, and interrupt acknowledge cycles to the timer.

8.3.9.1READ CYCLES. The timer is accessed with no wait states. The timer responds to byte, word, and long-word reads, and 16 bits of valid data are returned. Read cycles from reserved registers return logic zero.

8.3.9.2WRITE CYCLES. The timer is accessed with no wait states. The timer responds to byte, word, and long-word writes. Write cycles to read-only registers and bits as well as reserved registers complete in a normal manner without exception processing; however, the data is ignored.

8.3.9.3INTERRUPT ACKNOWLEDGE CYCLES. The timer is capable of arbitrating for interrupt servicing and supplying the interrupt vector when it has successfully won arbitration. The vector number must be provided if interrupt servicing is necessary; thus, the interrupt register (IR) must be initialized. If the IR is not initialized, a spurious interrupt exception will be taken if interrupt servicing is necessary.

8.4 REGISTER DESCRIPTION

The following paragraphs contain a detailed description of each register and its specific function. The operation of the timer is controlled by writing control words into the appropriate registers. Timer registers and their associated addresses are listed in Figure 8-11. For more information about a particular register, refer to the individual register description. The ADDR column indicates the offset of the register from the base address of the timer. An FC column designation of S indicates that register access is restricted to supervisor only. A designation of S/U indicates that access is governed by the SUPV bit in the module configuration register (MCR).

MOTOROLAMC68340 USER’S MANUAL8- 17

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Motorola MC68340 manual OCx Encoding, OC1 OC0 TOUTx
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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.
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