SAI_XCR1_MCKDIV_WIDTH
#define SAI_XCR1_MCKDIV_MAX(x) ((1 << SAI_XCR1_MCKDIV_WIDTH(x)) - 1)
mask = SAI_XCR1_MCKDIV_MASK(SAI_XCR1_MCKDIV_WIDTH(version));