9.5.2 Control B

Name: CTRLB
Offset: 0x01
Reset: 0x00
Property: Configuration Change Protection

Bit 76543210 
       BOOTLOCKAPCWP 
Access R/WR/W 
Reset 00 

Bit 1 – BOOTLOCK Boot Section Lock

Writing this bit to ‘1’ locks the BOOT section from reading and instruction fetching.

If this bit is ‘1’, a read from the BOOT section will return ‘0’. A fetch from the BOOT section will also return ‘0’ as instruction.

This bit can be written from the BOOT section only. It can only be cleared to ‘0’ by a Reset.

This bit will take effect only when the BOOT section is left the first time after the bit is written.

Bit 0 – APCWP Application Code Section Write Protection

Writing this bit to ‘1’ prevents further updates to the Application Code section.

This bit can only be written to ‘1’. It is cleared to ‘0’ only by Reset.