CHAPTER 17 FLASH MEMORY

17.4Confirming the Automatic Algorithm Execution State

Because the write/erase flow of the flash memory is controlled using the automatic algorithm, the flash memory has hardware for posting its internal operating state and completion of operation. This automatic algorithm enables confirmation of the operating state of the built-in flash memory using the following hardware sequence flags.

■Hardware Sequence Flags

The hardware sequence flags are configured from the five-bit output of DQ7, DQ6, DQ5, and DQ2. The functions of these bits are those of the data polling flag (DQ7), toggle bit flag (DQ6), timing limit exceeded flag (DQ5), and toggle bit2 flag (DQ2). The hardware sequence flags can therefore be used to confirm that writing or chip sector erase has been completed or that erase code write is valid.

The hardware sequence flags can be accessed by read-accessing the addresses of the target sectors in the flash memory after setting of the command sequence (see Table 17.3-1in Section "17.3 Starting the Flash Memory Automatic Algorithm "). Table 17.4-1lists the bit assignments of the hardware sequence flags.

Table 17.4-1 Bit Assignments of Hardware Sequence Flags

 

bit7

bit6

bit5

bit4

bit3

bit2

bit1

bit0

 

 

 

 

 

 

 

 

 

Hardware sequence flag

DQ7

DQ6

DQ5

-

-

DQ2

-

-

 

 

 

 

 

 

 

 

 

To determine whether automatic writing or chip sector erase is being executed, the hardware sequence flags can be checked or the status can be determined from the RDY bit of the flash memory control status register (FMCS) that indicates whether writing has been completed. After writing/erasing has terminated, the state returns to the read/reset state. When creating a program, use one of the flags to confirm that automatic writing/erasing has terminated. Then, perform the next processing operation, such as data read. In addition, the hardware sequence flags can be used to confirm whether the second or subsequent sector erase code write is valid. The following sections describe each hardware sequence flag separately. Table 17.4-2lists the functions of the hardware sequence flags.

Table 17.4-2 Hardware Sequence Flag Functions

 

State

DQ7

DQ6

DQ5

DQ2

 

 

 

 

 

 

 

 

 

Executing

Automatic writing operation

 

 

 

 

Toggle

0

1

 

DQ7

 

 

 

 

 

 

 

 

 

Automatic erasing operation

0

 

 

Toggle

0

Toggle

 

 

 

 

 

 

 

 

Exceeding

Automatic writing operation

 

 

 

Toggle

1

1

 

DQ7

the time limit

 

 

 

 

 

 

 

 

Automatic erasing operation

0

 

 

Toggle

1

Toggle

 

 

 

 

 

 

 

 

 

 

 

 

362

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Fujitsu MB89202, F202RA Confirming the Automatic Algorithm Execution State, Bit Assignments of Hardware Sequence Flags
Page 377 Page 379

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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