Atmel Evaluation Kit AT91SAM9X25-EK AT91SAM9X25-EK 데이터 시트
제품 코드
AT91SAM9X25-EK
771
SAM9X25 [DATASHEET]
11054E–ATARM–10-Mar-2014
38.11 Write Protection System
In order to bring security to the TWI, a write protection system has been implemented.
The write protection mode prevents the write of
. When this mode is enabled and one of the protected registers is written, an error is generated in the
and the register write request is canceled. When a write protection error occurs the
WPROTERR flag is set and the address of the corresponding canceled register write is available in the WPROTADRR
field of the TWI_WPROT_STATUS register.
field of the TWI_WPROT_STATUS register.
Due to the nature of the write protection feature, enabling and disabling the write protection mode requires the use of a
security code. Thus when enabling or disabling the write protection mode the SECURITY_CODE field of the
security code. Thus when enabling or disabling the write protection mode the SECURITY_CODE field of the
must be filled with the “TWI” ASCII code (0x545749) otherwise the register write will be
canceled.