6.6.1 Configuration Change Protection
Name: | CCP |
Offset: | 0x04 |
Reset: | 0x00 |
Property: | - |
Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
CCP[7:0] | |||||||||
Access | R/W | R/W | R/W | R/W | R/W | R/W | R/W | R/W | |
Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Bits 7:0 – CCP[7:0] Configuration Change Protection
Writing the correct signature to this bit field allows changing protected I/O registers or executing protected instructions within the next four CPU instructions executed.
All interrupts are ignored during these cycles. After these cycles are completed, the interrupts will automatically be handled by the CPU, and any pending interrupts will be executed according to their level and priority.
When the protected I/O register signature is written, CCP[0] will read
‘1
’ as long as the CCP feature is enabled.
When the protected self-programming signature is written, CCP[1] will read
‘1
’ as long as the CCP feature is enabled.
CCP[7:2] will always read ‘0
’.
Value | Name | Description |
---|---|---|
0x9D | SPM | Allow self-programming |
0xD8 | IOREG | Unlock protected I/O registers |