UPD78F9234MC-5A4-A Datasheet, PDF (307/419 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

CHAPTER 19 FLASH MEMORY
19.8.8 Example of byte write operation in self programming mode
An example of the byte write operation in self programming mode is explained below.
<1> Set 05H (byte write) to the flash program command register (FLCMD).
<2> Set the number of block to which data is to be written, to flash address pointer H (FLAPH).
<3> Set the address at which data is to be written, to flash address pointer L (FLAPL).
<4> Set the data to be written, to the flash write buffer register (FLW).
<5> Clear the flash status register (PFS).
<6> Write ACH to the watchdog timer enable register (WDTE) (clear and restart the watchdog timer counter)^Note.
<7> Execute the HALT instruction then start self programming. (Execute an instruction immediately after the
HALT instruction if self programming has been executed.)
<8> Check if a self programming error has occurred using bit 1 (VCERR) and bit 2 (WEPRERR) of PFS.
Abnormal → <9>
Normal → <10>
<9> Byte write processing is abnormally terminated.
<10> Byte write processing is normally terminated.
Note This setting is not required when the watchdog timer is not used.
Caution If a write results in failure, erase the block once and write to it again.
User’s Manual U17446EJ5V0UD
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