11.5.2 Control B
| Name: | CTRLB |
| Offset: | 0x01 |
| Reset: | 0x30 |
| Property: | Configuration Change Protection |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| FLMAPLOCK | FLMAP[1:0] | APPDATAWP | BOOTRP | APPCODEWP | |||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | |||
| Reset | 0 | 1 | 1 | 0 | 0 | 0 | |||
Bit 7 – FLMAPLOCK 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
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.
- For devices with Flash memory sizes up to 32 KB, all Flash is mapped to the CPU data space and changing this bit field value has no effect.
- For devices with 64
KB Flash memory,
SECTION0andSECTION2will map the first 32 KBs of Flash (0 - 32) whileSECTION1andSECTION3will map the last 32 KBs of Flash (32 - 64)
This bit field is not under Configuration Change Protection.
| Value | Name | Description |
|---|---|---|
| 0 | SECTION0 | The entire Flash section is mapped into the CPU data space. |
| 1 | SECTION1 | The entire Flash section is mapped into the CPU data space. |
| 2 | SECTION2 | The entire Flash section is mapped into the CPU data space. |
| 3 | SECTION3 | The entire Flash section is mapped into the CPU data space. |
Bit 2 – APPDATAWP 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
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
Writing this bit to ‘1’ prevents further updates to
the Application Code section. This bit can only be cleared by a Reset.