CHAPTER 3 CPU

➃The interrupt controller is always monitoring interrupt requests from peripheral functions. The interrupt controller notifies the CPU of the highest interrupt level interrupt among levels corresponding to interrupt requests currently generated. If different requests are made with the same interrupt level, the interrupt controller also determines their priorities.

➄The CPU checks the value in the interrupt enable flag (CCR: I) when the priority of the interrupt level that is received is higher (the level value is lower) than the level specified in the interrupt level bits in the condition code register (CCR: IL1 and IL0). The CPU then accepts the interrupt when the enable flag is turned on (CCR: I = 1).

➅Put the values in the program counter (PC) and program status (PS) in the stack, fetch the start address of the interrupt processing routine from the interrupt vector table concerned, change the value of the interrupt level bits in the condition code register (CCR: IL1 and IL0) to the value of the interrupt level accepted, and then start the interrupt processing routine.

➆Finally, restore the values of the program counter (PC) and program status (PS) put into the stack with the RETI instruction, then execute an instruction following the instruction executed immediately before the interruption.

Standby mode (low-power consumption mode) is cancelled by an interrupt. For details, see Section "3.7

Standby Mode (Low-Power Consumption Mode) ".

Notes:

•An interrupt request flag bit for a peripheral function is not automatically cleared even if the interrupt request is accepted. Therefore, it is necessary to clear the bit using a program in the interrupt processing routine (by writing "0" into the interrupt request flag bit normally).

•Clearing an interrupt request flag bit at the beginning of the interrupt processing routine allows the peripheral function that generated the interrupt to re-generate an interrupt (set an interrupt request flag bit again) while the interrupt processing routine is being executed. However, the re-generated interrupt is normally accepted after the interrupt processing routine ends its current cycle.

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Fujitsu MB89202, F202RA manual Cpu
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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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