Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.

IE2–IE0—Interrupt Enable

These bits determine which sources of interrupts, TO, TG, and TC, are enabled to generate an interrupt request to the CPU32. Table 8-3 lists which interrupts are enabled for all bit combinations.

Table 8-3. IEx Encoding

IE2

IE1

IE0

Enabled Interrupts

0

0

0

Polling Mode (No Interrupts Enabled)

0

0

1

TC Enabled

0

1

0

TG Enabled

0

1

1

TG and TC Enabled

1

0

0

TO Enabled

1

0

1

TO and TC Enabled

1

1

0

TO and TG Enabled

1

1

1

TO, TG, and TC Enabled

TGE—Timing Gate Enable

1 = The TGATE≈ signal is enabled to control the enabling and disabling of the prescaler and counter, except in the input capture/output compare mode (see 8.3.1 Input Capture/Output Compare).

0 = The TGATE≈ signal has no effect on the timer operation.

PCLK—Prescaler Clock Select

This bit selects which clock is used for the counter clock.

1 = The counter is decremented by the prescaler output tap as selected by the POT field in the CR.

0 = The counter is decremented by the selected clock.

The prescaler continues to decrement regardless of how PCLK is set.

CPE—Counter Prescaler Enable

1 = The selected clock is enabled. If the TGE bit is set, then TGATE≈ must also be asserted (except in the input capture/output compare mode).

0 = The selected clock is held high, halting the prescaler and counter.

CLK—Clock

1 = The selected clock is taken from the TINx input.

0 = The selected clock is one-half the system clock's frequency.

The TOUTx of one timer can be fed externally into the TINx input of the other timer, resulting in a 32-bit counter if the prescalers are not used and a 48-bit counter if they are used.

MOTOROLAMC68340 USER’S MANUAL8- 21

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Motorola MC68340 manual IEx Encoding, Enabled Interrupts
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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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