pub type CPHA_W<'a, const O: u8> = BitWriter<'a, u32, CONFIG_SPEC, CPHA_A, O>;
Field CPHA writer - Serial clock (SCK) phase
CPHA
struct CPHA_W<'a, const O: u8> { /* private fields */ }
Sample on leading edge of clock, shift serial data on trailing edge
Sample on trailing edge of clock, shift serial data on leading edge