Microchip Technology megaAVR 0 Series Manual page 58

7.7.1 Configuration Change Protection
Name: CCP
Offset: 0x04
Reset: 0x00
Property: -
Bit 7
Access R/W
Reset 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, interrupts will automatically be handled
again 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 as '1' as long as the CCP feature is
enabled.
When the protected self-programming signature is written, CCP[1] will read as '1' as long as the CCP
feature is enabled.
CCP[7:2] will always read as zero.
Value Name
0x9D SPM
0xD8 IOREG
©
2018 Microchip Technology Inc.
6 5
R/W R/W
0 0
Description
Allow Self-Programming
Un-protect protected I/O registers
4 3
CCP[7:0]
R/W R/W
0 0
Datasheet Preliminary
®
megaAVR 0-Series
AVR CPU
2 1
R/W R/W
0 0
DS40002015A-page 58
0
R/W
0