H8SSLASH2225 datasheet(821/1071 Pages) RENESAS

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Section 20 Flash Memory (F-ZTAT Version)

Rev. 5.00 Aug 08, 2006 page 735 of 982

REJ09B0054-0500

20.6.2

Programming/Erasing in User Program Mode

On-board programming/erasing of an individual flash memory block can also be performed in user

program mode by branching to a user program/erase control program. The user must prepare on-

board means for controlling FWE, on-board means of supplying programming data, and branching

conditions. The flash memory must contain the user program/erase control program or a program

that provides the user program/erase control program from external memory. As the flash memory

itself cannot be read during programming/erasing, transfer the user program/erase control program

to on-chip RAM, as in boot mode. Figure 20.8 shows a sample procedure for

programming/erasing in user program mode. Prepare a user program/erase control program in

accordance with the description in section 20.8, Flash Memory Programming/Erasing.

Yes

Program/erase?

Transfer user program/erase control

program to RAM

Reset-start

Branch to user program/erase control

program in RAM

Execute user program/erase control

program (flash memory rewrite)

Branch to flash memory application

program

Branch to flash memory application

program

Figure 20.8 Programming/Erasing Flowchart Example in User Program Mode

20.7

Flash Memory Emulation in RAM

A setting in the RAM emulation register (RAMER) enables part of RAM to be overlapped onto

the flash memory area so that data to be written to flash memory can be emulated in RAM in real

time. Emulation can be performed in user mode or user program mode. Figure 20.9 shows an

example of emulation of real-time flash memory programming.

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