ATtiny1616/3216

22.3.7 Configuration Change Protection

This peripheral has registers that are under Configuration Change Protection (CCP). In order to write to these, a certain key must be written to the CPU.CCP register first, followed by a write access to the protected bits within four CPU instructions.

Attempting to write to a protected register without following the appropriate CCP unlock sequence leaves the protected register unchanged.

The following registers are under CCP:

Table 22-9. TCD - Registers under Configuration Change Protection
Register	Key
FAULTCTRL	IOREG

The online versions of the documents are provided as a courtesy. Verify all content and data in the device’s PDF documentation found on the device product page.