CHAPTER 8 8/16-BIT CAPTURE TIMER/COUNTER

8.10Notes on Using 8/16-bit Capture Timer/Counter

This section provides notes on using the 8/16-bit capture timer/counter.

■Notes on Using the 8/16-bit Capture Timer/Counter

●Error

The start of the 8/16-bit capture timer/counter by a program is asynchronous with the start of the counter incremented by the selected count clock, and therefore, the error (a time difference) continues until the counter value matches the set data. Such a time difference may shorten the total count duration by a maximum of one count clock cycle. Figure 8.10-1shows the error (a time difference) that prolongs the actual start of count operation.

Figure 8.10-1 Error Occurring until the Count Operation is Started

Counter value

0

 

1

 

2

 

3

 

4

Count clock

1 cycle

Count 0

Error cycle

Counter start

●Using only timer 0 in 8-bit mode

When using only timer 0 of the 8/16-bit capture timer/counter in the 8-bit mode, set a value other than 111B in the count clock selection bits (TCS12, TCS11, TCS10) of the timer 1 control register (TCR1). Using timer 0 without setting 111B results in a malfunction.

●Note on setting by program

When using the 8/16-bit capture timer/counter in the 16-bit mode, set the count clock selection bits (TCS12, TCS11, TCS10) of TCR1 to 111B.

Before using the counter values when the counter is in operation with 16-bit mode, be sure to read the counter values twice and confirm that the values are valid.

Even if square wave output is initialized when the timer is in operation (TCR0: TSTR0 = 1), the output value is not modified. The output state is initialized when the timer operation stops.

When the interrupt request flag bits (TCCR: CPIF, TCR0: TIF0, TCR1: TIF1) are "1" and the interrupt

request enable bits are allowed (TCCR: CPIEN, TCR0: T0IEN, and TCR1: T1IEN = 1), return from an

interrupt is impossible. In this case, clear the interrupt request flag bits (TCCR: CFCLR = 1, TCR0: TFCR0 =

1, and TCR1: TFCR1 = 1).

198

Page 213 Page 215
Page 214
Image 214
Fujitsu MB89202, F202RA manual Error Occurring until the Count Operation is Started, Using only timer 0 in 8-bit mode
Page 213 Page 215

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.
Top Page Image Contents