# Enable-Protected Configuration

The configuration of the LUTs and sequencers is enable-protected, meaning that they can only be configured when the corresponding even LUT is disabled (ENABLE = ‘0’ in the LUT n Control A (CCL.LUTnCTRLA) register). This is a mechanism to suppress the undesired output from the CCL under (re-)configuration.

The following bits and registers are enable-protected:

• Sequencer Selection (SEQSEL) in the Sequencer Control n (CCL.SEQCTRLn) registers
• LUT n Control x (CCL.LUTnCTRLx) registers, except the ENABLE bit in the CCL.LUTnCTRLA register
• TRUTHn (CCL.TRUTHn) registers

The enable-protected bits in the CCL.LUTnCTRLx registers can be written at the same time as ENABLE in CCL.LUTnCTRLA is written to ‘1’, but not at the same time as ENABLE is written to ‘0’.

The enable protection is denoted by the enable-protected property in the register description.