Dedicated Register, Program counter PC | Fujitsu F202RA, MB89202

CHAPTER 3 CPU

3.2Dedicated Register

The dedicated register in the CPU consists of a program counter (PC), two arithmetic operation registers (A and T), three address pointers (IX, EP, and SP), and program status (PS) register. The size of each register is 16 bits.

■Dedicated Register Configuration

The dedicated register in the CPU consists of seven 16-bit registers. Some registers allow only the lower 8 bits to be used.

Figure 3.2-1shows the configuration of the dedicated register.

Figure 3.2-1 Configuration of Dedicated Register

Initial value	16 bits
FFFDH		PC


Undefined		A
Undefined		T

Undefined		IX

Undefined		EP
Undefined		SP

Flag I = 0	RP		CCR

IL1 and IL0 = 11		PS
The other bits are undefined.

:Program counter

Indicates the current instruction stored position.

:Accumulator

Temporary register that handles arithmetic operations and data transfer.

:Temporary accumulator

Handles arithmetic operations together with the accumulator.

:Index register

Indicates index address.

:Extra-pointer

Indicates memory address.

:Stack pointer

Indicates the current position in the stack.

:Program status register

Stores the register bank pointer and condition code.

■Functions of the Dedicated Register

●Program counter (PC)

The size of the program counter is 16 bits. It indicates the memory address at which the CPU is currently handling an instruction. The program counter is updated with an instruction executed, interrupt, or reset. The initial value specified after the reset operation is the mode data read address (FFFDH).

●Accumulator (A)

The accumulator is a 16-bit arithmetic operation register. It handles arithmetic operations or data transfer using data on memory or data in another register such as temporary accumulator (T). The accumulator allows data in it to be used as a word (16 bits) or bytes (8 bits). When arithmetic operations or data transfer is handled in the unit of a byte, only the lower 8 bits (AL) of the accumulator are used; the upper 8 bits (AH) remain unchanged. The initial value specified after the reset operation is undefined.

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.

Fujitsu F202RA manual Functions of the Dedicated Register, Program counter PC, Accumulator a

Models: F202RA MB89202