Function ticksToNs

src/platforms/arm/lpc/rx_sct_capture.cpp.hpp:224–229

Convert an unsigned tick delta (free-running 32-bit SCT counter, F_CPU ticks) to nanoseconds. F_CPU is the SCT clock when CLKMODE=0; on LPC845-BRK that is 30_000_000 Hz, giving 33.33 ns per tick. Compute with u64 to avoid mid-multiplication overflow at the long-period extreme: a full 32-bit tick wrap at 30 MHz is ~143 s = 1.43e11 ns, which fits u64 with margin. EdgeTime.ns is a 31-bit bitfield (ma

// fits u64 with margin. EdgeTime.ns is a 31-bit bitfield (max ~2.1 s) so
// we saturate above that.
inline fl::u32 ticksToNs(fl::u32 ticks) FL_NOEXCEPT {
    constexpr fl::u32 kFcpuMHz = (F_CPU + 500000u) / 1000000u;  // 30 on LPC845
    fl::u64 ns64 = (static_cast<fl::u64>(ticks) * 1000u + (kFcpuMHz / 2)) / kFcpuMHz;
    if (ns64 > 0x7FFFFFFFull) ns64 = 0x7FFFFFFFull;
    return static_cast<fl::u32>(ns64);
}

#if defined(FASTLED_LPC_RX_SCT_DMA)
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