Control B

Name:
CTRLB
Offset:
0x01
Reset:
0x30
Access:
Configuration Change Protection
Bit76543210
FLMAPLOCKFLMAP[1:0]APPDATAWPBOOTRPAPPCODEWP
AccessR/WR/WR/WR/WR/WR/W
Reset011000

Bit 7 – FLMAPLOCK: Flash Mapping Lock

Flash Mapping Lock

Setting this bit to ‘1’ prevents further updates of FLMAP[1:0]. This bit can only be cleared by a Reset.

Bits 5:4 – FLMAP[1:0]: Flash Section Mapped into Data Space

Flash Section Mapped into Data Space

Select what part (in blocks of 32 KB) of the Flash will be mapped as part of the CPU data space and will be accessible through LD/ST instructions.

This bit field is not under Configuration Change Protection.

Value Name Mapped Flash Section (KB)
8 KB Flash 16 KB Flash 32 KB Flash 64 KB Flash
0 SECTION0 0-8 0-16 0-32 0-32
1 SECTION1 32-64
2 SECTION2 0-32
3 SECTION3 32-64

Bit 2 – APPDATAWP: Application Data Section Write Protection

Application Data Section Write Protection

Writing this bit to ‘1’ prevents further updates to the Application Data section. This bit can only be cleared by a Reset.

Bit 1 – BOOTRP: Boot Section Read Protection

Boot Section Read Protection

Writing this bit to ‘1’ will protect the BOOT section from reading and instruction fetching. If a read is issued from the other Flash sections, it will return ‘0’. An instruction fetch from the BOOT section will return a NOP instruction. This bit can only be written from the BOOT section, and it can only be cleared by a Reset. The read protection will only take effect when leaving the BOOT section after the bit is written.

Bit 0 – APPCODEWP: Application Code Section Write Protection

Application Code Section Write Protection

Writing this bit to ‘1’ prevents further updates to the Application Code section. This bit can only be cleared by a Reset.