LPC1766串口发送后接收乱码问题

最近使用LPC1766芯片遇到一个问题，用硬件仿真看串口发送前数据是正确的，但是用TTL-USB发送到电脑后接收乱码。使用基础串口发送代码也是这个问题。
使用12M外部晶振。各位大神有知道原因的吗？万分感谢

主程序

int main(void)
{
uint32_t i,j, k=0;
SystemInit();
UART0_Init(9600);
UART0_SendString("hello world");
Delay(250);
}

串口配置

#define FOSC 12000000
#define FCCLK (FOSC * 8)
#define FCCO (FCCLK * 3)
#define FPCLK (FCCLK / 4)
void UART0_Init (uint32_t baudrate)
{
uint16_t usFdiv;
/* UART0 */
LPC_PINCON->PINSEL0 |= (1 << 4);
LPC_PINCON->PINSEL0 |= (1 << 6);
LPC_UART0->LCR = 0x83;
usFdiv = (FPCLK / 16) / baudrate;
LPC_UART0->DLM = usFdiv / 256;
LPC_UART0->DLL = usFdiv % 256;
LPC_UART0->LCR = 0x03;
LPC_UART0->FCR = 0x06;
}

系统初始化代码

#if (CLOCK_SETUP) /* Clock Setup */
LPC_SC->SCS = SCS_Val;
if (SCS_Val & (1 << 5)) { /* If Main Oscillator is enabled */
while ((LPC_SC->SCS & (1<<6)) == 0);/* Wait for Oscillator to be ready */
}
LPC_SC->CCLKCFG = CCLKCFG_Val; /* Setup Clock Divider */
#if (PLL0_SETUP)
LPC_SC->CLKSRCSEL = CLKSRCSEL_Val; /* Select Clock Source for PLL0 */
LPC_SC->PLL0CFG = PLL0CFG_Val; /* configure PLL0 */
LPC_SC->PLL0FEED = 0xAA;
LPC_SC->PLL0FEED = 0x55;
LPC_SC->PLL0CON = 0x01; /* PLL0 Enable */
LPC_SC->PLL0FEED = 0xAA;
LPC_SC->PLL0FEED = 0x55;
while (!(LPC_SC->PLL0STAT & (1<<26)));/* Wait for PLOCK0 */
LPC_SC->PLL0CON = 0x03; /* PLL0 Enable & Connect */
LPC_SC->PLL0FEED = 0xAA;
LPC_SC->PLL0FEED = 0x55;
while (!(LPC_SC->PLL0STAT & ((1<<25) | (1<<24))));/* Wait for PLLC0_STAT & PLLE0_STAT */
#endif
#if (PLL1_SETUP)
LPC_SC->PLL1CFG = PLL1CFG_Val;
LPC_SC->PLL1FEED = 0xAA;
LPC_SC->PLL1FEED = 0x55;
LPC_SC->PLL1CON = 0x01; /* PLL1 Enable */
LPC_SC->PLL1FEED = 0xAA;
LPC_SC->PLL1FEED = 0x55;
while (!(LPC_SC->PLL1STAT & (1<<10)));/* Wait for PLOCK1 */
LPC_SC->PLL1CON = 0x03; /* PLL1 Enable & Connect */
LPC_SC->PLL1FEED = 0xAA;
LPC_SC->PLL1FEED = 0x55;
while (!(LPC_SC->PLL1STAT & ((1<< 9) | (1<< 8))));/* Wait for PLLC1_STAT & PLLE1_STAT */
#else
LPC_SC->USBCLKCFG = USBCLKCFG_Val; /* Setup USB Clock Divider */
#endif
LPC_SC->PCLKSEL0 = PCLKSEL0_Val; /* Peripheral Clock Selection */
LPC_SC->PCLKSEL1 = PCLKSEL1_Val;
LPC_SC->PCONP = PCONP_Val; /* Power Control for Peripherals */
LPC_SC->CLKOUTCFG = CLKOUTCFG_Val; /* Clock Output Configuration */
#endif
#if (FLASH_SETUP == 1) /* Flash Accelerator Setup */
LPC_SC->FLASHCFG = FLASHCFG_Val;
#endif
}