S_DUART_BITS_PER_CHAR
#define M_DUART_BITS_PER_CHAR _SB_MAKEMASK(2, S_DUART_BITS_PER_CHAR)
#define V_DUART_BITS_PER_CHAR(x) _SB_MAKEVALUE(x, S_DUART_BITS_PER_CHAR)