CHAPTER 3 CPU

3.5.3Reset Operation

The CPU reads the mode data (mode fetch) and reset vector from internal ROM according to the mode pin settings following the cancellation of a reset. For a return triggered by a reset when power is turned on and in stop mode, the CPU fetches the mode after oscillation stabilization wait time has expired. When a reset occurs, the contents in RAM cannot be guaranteed.

■Overview of the Reset Operation

Figure 3.5-3 Reset Operation Flow

Software reset

 

External reset input

Watchdog reset

 

 

 

 

Power-on

 

 

reset selected?

Being reset

 

YES

NO

 

 

When power

 

 

 

 

is turned on or in stop

 

 

mode?

 

 

YES

State of reset wait-

 

State of reset wait-

ing for stabilization

 

ing for stabilization

of oscillation

 

of oscillation

 

 

External reset

 

 

state cancelled?

 

 

YES

Power-on reset

State of reset wait- ing for stabilization of oscillation

NO

Mode fetch (reset operation)

Normal operation (RUN mode)

Mode data fetch

Reset vector fetch

Instruction code fetched from the address that indicates the reset vector; the instruction is then executed.

48

Page 63 Page 65
Page 64
Image 64
Fujitsu MB89202, F202RA manual Reset Operation Flow
Page 63 Page 65

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