Function writeLutInputMux

src/platforms/arm/lpc/clockless_arm_lpc_plu.h:141–146

LUTn_INP_MUX[m] write helper. sel: 0..5 -> primary input PLU_IN0..PLU_IN5 6..N -> LUT[sel-6] output (UM11065 §12.6.1 mux encoding)

// sel: 0..5 -> primary input PLU_IN0..PLU_IN5
//      6..N -> LUT[sel-6] output (UM11065 §12.6.1 mux encoding)
static inline void writeLutInputMux(fl::u8 lut, fl::u8 input_idx,
                                    fl::u8 sel) FL_NOEXCEPT {
    // Stride is 5 u32 per LUT (one per input).
    fl::u32 off = kOffLutInpMux0 + (fl::u32(lut) * 5UL + input_idx) * 4UL;
    *reg32(kPluBase, off) = sel;
}

// OUTPUTm_MUX write helper. Selects which LUT drives PLU_OUTm.
static inline void writeOutputMux(fl::u8 out_idx, fl::u8 lut_sel) FL_NOEXCEPT {