UART_DM_IPR
volatile uint32_t * UART_DM_IPR = (uint32_t *)(UART_BASE + 0x18);
*UART_DM_IPR = UART_DM_STALE_TIMEOUT_LSB;
uart_setreg(bas, UART_DM_IPR, UART_DM_STALE_TIMEOUT_LSB);