你好,楼主!
你可以试试以下的代码来配置波特率看看。
void uart_init (UART_MemMapPtr uartch, int sysclk, int baud)
{
register uint16 sbr, brfa;
uint8 temp;
/* Enable the clock to the selected UART */
if(uartch == UART0_BASE_PTR)
SIM_SCGC4 |= SIM_SCGC4_UART0_MASK;
else
if (uartch == UART1_BASE_PTR)
SIM_SCGC4 |= SIM_SCGC4_UART1_MASK;
else
if (uartch == UART2_BASE_PTR)
SIM_SCGC4 |= SIM_SCGC4_UART2_MASK;
else
if(uartch == UART3_BASE_PTR)
SIM_SCGC4 |= SIM_SCGC4_UART3_MASK;
else
if(uartch == UART4_BASE_PTR)
SIM_SCGC1 |= SIM_SCGC1_UART4_MASK;
else
SIM_SCGC1 |= SIM_SCGC1_UART5_MASK;
/* Make sure that the transmitter and receiver are disabled while we
* change settings.
*/
UART_C2_REG(uartch) &= ~(UART_C2_TE_MASK
| UART_C2_RE_MASK );
/* Configure the UART for 8-bit mode, no parity */
UART_C1_REG(uartch) = 0; /* We need all default settings, so entire register is cleared */
/* Calculate baud settings */
sbr = (uint16)((sysclk*1000)/(baud * 16));
/* Save off the current value of the UARTx_BDH except for the SBR field */
temp = UART_BDH_REG(uartch) & ~(UART_BDH_SBR(0x1F));
UART_BDH_REG(uartch) = temp | UART_BDH_SBR(((sbr & 0x1F00) >> 8));
UART_BDL_REG(uartch) = (uint8)(sbr & UART_BDL_SBR_MASK);
/* Determine if a fractional divider is needed to get closer to the baud rate */
brfa = (((sysclk*32000)/(baud * 16)) - (sbr * 32));
/* Save off the current value of the UARTx_C4 register except for the BRFA field */
temp = UART_C4_REG(uartch) & ~(UART_C4_BRFA(0x1F));
UART_C4_REG(uartch) = temp | UART_C4_BRFA(brfa);
/* Enable receiver and transmitter */
UART_C2_REG(uartch) |= (UART_C2_TE_MASK
| UART_C2_RE_MASK );
}
/**
|