Initialization

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:

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

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

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