EFM32片內外設–LEUart之基本操作

LEUart 最基本的常式：

硬體準備： TG STK， LEUart0， Tx：PD4， Rx：PD5.  TG STK的20pin擴充口上已經有這兩個IO口，分別是12Pin（PD4），14Pin（PD5）。

軟體常式：

#include <stdint.h>
#include <stdbool.h>
#include "efm32.h"
#include "efm32_chip.h"
#include "efm32_cmu.h"
#include "efm32_leuart.h"
#include "efm32_gpio.h"

unsigned char ucString[] = {
    "Hello world,This is a test for LEUart from Gecko.\r\n"
};

#define LINK_UART_TX_PORT           gpioPortD
#define LINK_UART_TX_BIT            4
#define LINK_UART_TX_MODE           gpioModePushPull

#define LINK_UART_RX_PORT           gpioPortD
#define LINK_UART_RX_BIT            5
#define LINK_UART_RX_MODE           gpioModeInputPull

#define LINK_CMU_UART               cmuClock_LEUART0
#define LINK_UART                   LEUART0
#define LINK_UART_ROUTE_EN          LEUART_ROUTE_TXPEN | LEUART_ROUTE_RXPEN
#define LINK_UART_ROUTE_LOCATION    LEUART_ROUTE_LOCATION_LOC0

#define LINK_REF_FREQUENCY          CMU_ClockFreqGet(LINK_CMU_UART)

#define LINK_UART_IRQ               LEUART0_IRQn

#define LEUART_STATUS               LEUART0->STATUS
#define UARTTXC                     0x08

void LEUart_Init(void)
{
    CMU_ClockEnable(cmuClock_HFPER, true);
    CMU_ClockEnable(cmuClock_GPIO, true);
    CMU_ClockEnable(cmuClock_CORELE, true);
   
    CMU_ClockSelectSet(cmuClock_LFB, cmuSelect_LFXO);
    CMU_ClockEnable(cmuClock_LEUART0, true);
   
    /* Defining the LEUART1 initialization data */
    LEUART_Init_TypeDef leuart1Init =
    {
        .enable   = leuartEnable,         /* Activate data reception on LEUn_TX pin. */
        .refFreq  = LINK_REF_FREQUENCY,   /* Inherit the clock frequenzy from the LEUART clock source */
        .baudrate = 9600,                 /* Baudrate = 9600 bps */
        .databits = leuartDatabits8,      /* Each LEUART frame containes 8 databits */
        .parity   = leuartNoParity,       /* No parity bits in use */
        .stopbits = leuartStopbits1,      /* Setting the number of stop bits in a frame to 2 bitperiods */
    };
   
    LEUART_Init_TypeDef Leuart_Init = leuart1Init;
   
    /* Reseting and initializing LEUART1 */
    LEUART_Reset(LINK_UART);
   
    /* Route LEUART1 TX pin to DMA location 0 */
    LINK_UART->ROUTE = LINK_UART_ROUTE_EN | LINK_UART_ROUTE_LOCATION;
   
    LEUART_Init(LINK_UART, &Leuart_Init);
   
    //LEUART_IntEnable(LINK_UART, LEUART_IEN_RXDATAV);
   
    //NVIC_SetPriority(LINK_UART_IRQ,7);
    /* Enable LEUART1 interrupt vector */
    //NVIC_EnableIRQ(LINK_UART_IRQ);
   
    /* Enable GPIO for LEUART0.  */
    GPIO_PinModeSet(LINK_UART_TX_PORT, LINK_UART_TX_BIT, LINK_UART_TX_MODE, 1);
    GPIO_PinModeSet(LINK_UART_RX_PORT, LINK_UART_RX_BIT, LINK_UART_RX_MODE, 1);
}

/**************************************************************************//**
 * @brief  Main function
 *****************************************************************************/
int main(void)
{
    /* Chip errata */
    CHIP_Init();
    LEUart_Init();
   
    while(1)
    {
        unsigned long ulDelay = 100000;
        while(ulDelay--);
        for(unsigned char i = 0; i < 53; i++)
        {
            LEUART_Tx(LINK_UART, ucString[i]);
        }
    }
}

以上是基本的LEUart的Demo。