CHAPTER 5 TIME-BASE TIMER

5.1Overview of Time-base Timer

The time-base timer functions as an interval timer. The time-base timer is a 21-bit free- run counter that counts up in synchronization with the internal count clock (at the oscillation frequency divided by 2). The timer also has an interval timer function to select one of four time intervals. In addition, it provides timer output for oscillation stabilization time and an operation clock for the watchdog timer.

The time-base timer stops operating in modes in which oscillation stops.

■Interval Timer Function

The interval timer function is used to continuously generate interrupts at specified intervals.

•An interrupt occurs when the interval timer bits of the time-base timer counter overflow.

•One of four time intervals can be selected by setting the interval timer bits.

Table 5.1-1lists the time intervals for the time-base timer.

Table 5.1-1 Time Intervals for Time-base Timer

Internal count clock cycle

Time interval

213/FCH (Approximately 0.66 ms)

2/FCH (0.16 ∝s)

215/FCH (Approximately 2.6 ms)

218/FCH (Approximately 21.0 ms)

222/FCH (Approximately 335.5 ms)

FCH: Oscillation frequency

The values enclosed in parentheses are time intervals when the oscillation frequency is 12.5 MHz.

■Clock Supply Function

The clock supply function is used to provide one of three timer outputs for the oscillation stabilization wait time and the operation clock for the resource function.

Table 5.1-2lists cycles of the clock that the time-base timer supplies to peripherals.

Table 5.1-2 Clock Cycles Supplied by Time-base Timer (1/2)

Clock supplied to

 

 

Clock cycle

Remarks

 

 

 

 

214/FCH (Approximately 1.31 ms)

Selected by the oscillation stabilization time

Oscillation

 

 

 

217/F

 

 

CH

(Approximately 10.49 ms)

selection bits (SYCC: WT1, WT0) of the clock

stabilization time

 

 

control section system clock control register.

 

218/FCH (Approximately 20.97 ms)

 

 

 

 

 

 

 

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Fujitsu MB89202 Overview of Time-base Timer, Clock Supply Function, TIME-BASE Timer, Time Intervals for Time-base Timer
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F202RA, MB89202 specifications

The Fujitsu MB89202 and F202RA microcontrollers are part of the 16-bit microcontroller family, renowned for their robust performance and versatility in a variety of embedded system applications. These devices are tailored for high-efficiency operation across diverse industries, including automotive, consumer electronics, and industrial automation.

One of the main features of the MB89202 is its powerful CPU core, which operates at a clock speed of up to 20 MHz. This enables the microcontroller to perform complex calculations and consumer-grade applications seamlessly. The architecture is designed to handle multiple tasks effectively, making it suitable for real-time operations.

Memory capacity is a vital characteristic of the MB89202, featuring on-chip RAM and ROM configurations. The microcontroller can accommodate different memory variants, providing developers with flexibility in memory allocation based on their application requirements. This adaptability facilitates applications ranging from simple control systems to complex data processing tasks.

The F202RA variant extends the capabilities of the MB89202 by integrating advanced peripheral functions. It includes built-in timers, A/D converters, and serial communication interfaces, which are essential for interfacing with other hardware components or sensors. The availability of these peripherals reduces the need for additional external circuits, thus contributing to a more compact and cost-effective design.

In terms of power management, the MB89202 series employs advanced power-saving technologies. The microcontroller offers various low-power modes, enabling devices to conserve energy during idle times, making it highly suitable for battery-operated applications. This characteristic not only enhances the efficiency of devices but also extends their operational lifespan.

Moreover, the Fujitsu MB89202 series incorporates robust protection features, including watchdog timers and failure detection mechanisms. These safety features ensure reliable operation in critical systems, making them a preferred choice in applications where failure is not an option.

The MB89202 and F202RA microcontrollers also support a range of development tools and environments, including integrated development environments (IDEs) and software libraries, which facilitate rapid application development. With these tools, developers can efficiently prototype, debug, and optimize their applications.

In summary, the Fujitsu MB89202 and F202RA microcontrollers stand out with their efficient performance, extensive memory options, integrated peripherals, and power-saving capabilities, making them ideal for a wide array of embedded applications. Their reliability and robustness further enhance their attractiveness for designers seeking advanced microcontroller solutions.
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