REG_SET
#define REG_SET(FIELD, v) (((v) << FIELD##_SHIFT) & FIELD##_MASK)
#undef REG_SET
#define REG_SET(reg_name, initial_val, field, val) \
#define REG_SET(reg_name, initial_val, field, val) \
#define REG_SET(FIELD, v) (((v) << FIELD##_SHIFT) & FIELD##_MASK)