pin init effect the UART print

it is the inresting issue .when i initial the pin ,it will affect the print of uart0. or the UART0 print function just stop.

but i see the real pin connect to the uart0 is PIN_55,PIN_57.

why i config orther pin will effect thoes two pins.

i saw the PDF，and find some relation to the UART0

here is my way i init .

/********************rotate button code*************************************/
// RS1 = 0x5, /* RS1/GP5/Pin60 */
// RS2 = 0x6, /* RS2/GP6/Pin61 */
// RS3 = 0x7, /* RS3/GP7/Pin62*/

// MAP_PinTypeGPIO(PIN_60, PIN_MODE_0, false);
// MAP_GPIODirModeSet(GPIOA0_BASE, 0x20, GPIO_DIR_MODE_IN);
// MAP_PinTypeGPIO(PIN_61, PIN_MODE_0, false);
// MAP_GPIODirModeSet(GPIOA0_BASE, 0x40, GPIO_DIR_MODE_IN);
// MAP_PinTypeGPIO(PIN_62, PIN_MODE_0, false);
// MAP_GPIODirModeSet(GPIOA0_BASE, 0x80, GPIO_DIR_MODE_IN);

// MAP_PinTypeGPIO(PIN_50, PIN_MODE_0, false);
// MAP_GPIODirModeSet(GPIOA0_BASE, 0x00, GPIO_DIR_MODE_OUT);