CHAPTER 14 8-BIT SERIAL I/O

14.1Overview of 8-Bit Serial I/O

The 8-bit serial I/O has a function that serially transfers 8-bit data in synchronization with a shift clock. It can select one shift clock from three internal shift clocks and one external shift clock. It can also select LSB first or MSB first as the data shift direction.

■Serial I/O Function

The 8-bit serial I/O function serially inputs and outputs 8-bit data in synchronization with a shift clock.

•Converts 8-bit parallel data to 8-bit serial data and outputs it. Also inputs 8-bit serial data, converts the data to 8-bit parallel data, and stores it.

•Can select one shift clock from three internal shift clocks and one external shift clock.

•Can control shift clock input/output and output internal shift clocks.

•Can select LSB first or MSB first as the data shift direction.

Table 14.1-1 Shift Clock Cycle and Transfer Rate

Shift clock

Clock cycle

Frequency (Hz)

Transfer rate

(FCH=12.5MHz, At maximum speed*)

 

 

 

 

 

 

 

 

2tINST

1/ (2tINST)

1562.5 kbps

Internal shift clock

 

 

 

8tINST

1/ (8tINST)

390.6 kbps

(output)

 

 

 

 

32tINST

1/ (32tINST)

97.66 kbps

External shift clock

2tINST or lower

1/(2tINST) or lower

DC to 1562.5 kbps

(input)

 

 

 

 

 

 

 

FCH : Oscillation frequency

tINST : Instruction cycle

*: When the highest speed clock of a general mode is selected with the system clock control register (SYCC) (CS1 and CS0 bits of SYCC = 11B, 1 instruction cycle = 4/FCH)

■Serial Function Switching

The 8-bit serial I/O and UART cannot be used simultaneously because they use the same pin. For this reason, the serial function switching circuit must be used to switch the 8-bit serial I/O and UART. For more information on the serial function switching circuit, see Section "13.4.7 Serial Switch Register (SSEL) ".

Selecting the 8-bit serial I/O with this serial function switching circuit enables P30/UCK/SCK to be used as the serial clock I/O pin (SCK) of the serial I/O, and P31/UO/SO to be used as the data output pin (SO). This selection also enables P32/UI/SI to be used as the data input pin (SI).

Note:

This chapter describes pin function switching and the register function, etc., on the assumption that the 8- bit serial I/O is selected with the serial function switching circuit.

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Fujitsu MB89202, F202RA manual Overview of 8-Bit Serial I/O, Serial Function Switching, BIT Serial I/O
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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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