LPC54100 LPC54101 LPC54102 LPC541xx series serial port usage

LPC54100 LPC54101 LPC54102 LPC541xx series serial port usage

(Using library, interrupt mode, no FIFO)

// Initialization function

void uart_init(baudRate)

{

    UART_BAUD_T baud;

    UART_CFG_T cfg;

    // Enable the clock

    Chip_Clock_EnablePeriphClock(SYSCON_CLOCK_FRG);

    //Configure baud rate

    //Get the clock frequency

    baud.clk = Chip_Clock_GetAsyncSyscon_ClockRate();

    //Desired baud rate

    baud.baud = baudRate;

    baud.ovr = 0;

    baud.mul = 0;

    baud.div = 0;

    if (ROM_UART_CalBaud(&baud) != LPC_OK) {

        // Failed to calculate the frequency division coefficient

        printf("Error calculating baud ratern");

    }

    /* Set the fractional divider */

    Chip_SYSCON_SetUSARTFRGCtrl(baud.mul, 0xFF);

    // Enable serial port 0 clock

    Chip_Clock_EnablePeriphClock(SYSCON_CLOCK_USART0);

    //Configure IO ports P0.0 and P0.1 as serial port functions

    Chip_IOCON_PinMuxSet(LPC_IOCON, 0, 0, (IOCON_FUNC1 | IOCON_MODE_INACT | IOCON_DIGITAL_EN));

    Chip_IOCON_PinMuxSet(LPC_IOCON, 0, 1, (IOCON_FUNC1 | IOCON_MODE_INACT | IOCON_DIGITAL_EN));

    //Get the space required by the serial port

    size = ROM_UART_GetMemSize();

    //Apply for the space required by the serial port

    drv_mem = (uint32_t *)malloc(size);

    //Call the initialization function to initialize serial port 0

    UART0 = ROM_UART_Init(drv_mem, LPC_USART0_BASE, NULL);

    //Configure the serial port

    //8-bit data enable receive interrupt

    cfg.cfg = UART_CFG_8BIT | UART_CFG_BRKRX;

    //Set the frequency division value, directly use the result calculated by ROM_UART_CalBaud

    cfg.div = baud.div;

    cfg.ovr = baud.ovr;

    cfg.res = UART_BIT_DLY(baudRate);

    //Configure serial port 0

    ROM_UART_Configure(UART0, &cfg);

    // Enable interrupt

    NVIC_ClearPendingIRQ(UART0_IRQn);

    NVIC_EnableIRQ(UART0_IRQn);

    LPC_USART0->INTENSET |= (1<<0);

}

//Interrupt service function

void UART0_IRQHandler(void)

{   

    uint8_t that;

    //Send interrupt

    if (LPC_USART0->INTSTAT & (1<<2))

    {

        //Wait for sending to complete

        ROM_UART_WaitTx(UART0);

    }

    //Receive interrupt

    if (LPC_USART0->INTSTAT & (1<<0))

    {

        //Read data

        dat = LPC_USART0->RXDAT;

        printf("%c", dat);

    }

}