ATtiny1624/1626/1627

CCP

Configuration Change Protection

  0x04 8 - 0x00    

Configuration Change Protection

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

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’.

ValueNameDescription
0x9D SPM Allow self-programming
0xD8 IOREG Unlock protected I/O registers