CHAPTER 14 8-BIT SERIAL I/O

●Shift clock control circuit

As a shift clock of the shift clock control circuit, one of three internal clocks and one external clock is selected.

Selecting an internal clock enables the shift clock to be output to the SCK pin. Selecting an external clock enables the clock to be input from the SCK pin to act as the shift clock. The shift clock control circuit shifts the SDR in accordance with this shift clock and outputs the shifted-out value to the SO pin. It also captures the data input from the SI pin while shifting it to the SDR.

●Shift clock counter

The shift clock counter counts the number of times the SDR was shifted using the shift clock. When 8-bit shift is completed, the counter overflows.

When the counter overflows, the serial I/O transfer start bit of the SMR (SST = 0) is cleared and the interrupt request flag bit (SIOF = 1) is set. When serial transfer stops (SST = 0), the counter stops its count. It is cleared when serial transfer is started (SST = 1).

●Serial data register (SDR)

The SDR retains transfer data. The data written to the SDR is converted to serial data and output. Serial input is converted to parallel data and stored.

●Serial mode register (SMR)

The SMR is a serial I/O control register. It is used to allow and prohibit serial I/O operation, select shift clocks, and set a transfer (shift) direction. It is also used to control interrupts and check interrupt states.

●8-bit serial I/O interrupt

•IRQC: If the interrupt request output is allowed (SMR: SIOE = 1) when the I/O function of the 8-bit serial I/O inputs or outputs 8-bit serial data, a interrupt request (IRQC) is generated.

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Fujitsu MB89202 Shift clock control circuit, Shift clock counter, Serial mode register SMR, Bit serial I/O interrupt, 316
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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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