TMP86FM25F datasheet(13/53 Pages) TOSHIBA

13 / 53 page

TMP86FM25

2004-03-01

86FM25-12

Under development

1.2.3

FLASH Write Enable Control (EEPCR<EEPMD>)

In the FLASH product, the control register can be used to disable a write to the FLASH

(Write protect) in order to prevent a write to the FLASH from occurring by mistake because

of a program error or microcontroller malfunction. To enable a write to the FLASH, set the

EEPCR<EEPMD> with 0011B. To disable a write to the FLASH, set the EEPCR<EEPMD>

with 1100B. A reset initializes the EEPCR<EEPMD> to 1100B to disable a write to the

FLASH. Usually, set the EEPCR<EEPMD> with 1100B, except when it is necessary to

write to the FLASH.

Note 1: The FLASH memory (8000H to FFFFH) can be written only in the serial PROM mode.

Note 2: The EEPCR<EEPMD> can be rewritten only when a program is being executed in the

RAM area. Executing a write instruction to the EEPCR<EEPMD> in the FLASH area

does not change its setting.

Note 3: In the TMP86CM25A, executing a write instruction to the EEPCR<EEPMD> changes its

setting; however, the new setting does not take effect.

Note 4: This function can be used in serial PROM mode. In MCU mode, the EEPCR<EEPMD>

should be always set to “1100B”.

TMP86FM25F Datasheet(PDF) 13 Page - Toshiba Semiconductor