Dear Peter thank you for your response,
Actually, I read this document and WLS is set as 1, and WL1 AND WL0 are set as 1. However, in this configuration it does not work.
LINFlexD_14.LINCR1.R = 1;
LINFlexD_14.UARTCR.R = 1;
LINFlexD_14.UARTCR.B.WLS = 1;
LINFlexD_14.UARTCR.B.SBUR = 1;
LINFlexD_14.UARTCR.B.WL0 = 1;
LINFlexD_14.UARTCR.B.WL1 = 1;
LINFlexD_14.LINFBRR.R = (uint16_t)(div & 15U); /* Fractional divider. */
LINFlexD_14.LINIBRR.R = (uint16_t)(div >> 4); /* Integer divider. */
LINFlexD_14.UARTSR.R = 0xFFFF;
LINFlexD_14.UARTCR.B.RFBM = 1U;
LINFlexD_14.LINCR1.R = 0;
My configuration as above. However, it does not work. When WL0 is set 1 and WL1 is set 0, I can receive data, but these data are missing and confusing.