LM3S9B90 UART receive wrong data

Hi,

I am now using LM3S9B90 to develop our company’s products. I used UART1 ro received data from PC side COM port (a program written by C# that keeps sending data to M3 with 10400 8n1 speed, no s/w and h/w handshaking). The UART1 initialization code of UART1 is as follows:

void uart1(void)

{

    /* Configure the UART 1. */

    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);

    GPIOPinConfigure(GPIO_PD2_U1RX);

    GPIOPinConfigure(GPIO_PD3_U1TX);

    GPIOPinTypeUART(GPIO_PORTD_BASE, GPIO_PIN_2 | GPIO_PIN_3);

    SysCtlPeripheralEnable(SYSCTL_PERIPH_UART1);

    SysCtlPeripheralReset(SYSCTL_PERIPH_UART1);

    UARTConfigSetExpClk(UART1_BASE, SysCtlClockGet(), UART1_BAUD, (UART_CONFIG_WLEN_8 | UART_CONFIG_STOP_ONE | UART_CONFIG_PAR_NONE));

    //UARTIntRegister(UART1_BASE, uart1_int_handler);

    IntEnable(INT_UART1);

    UARTIntEnable(UART1_BASE, UART_INT_RX | UART_INT_RT);

    //IntPrioritySet(INT_UART1, 0x80);

}

Test1:

I was using pl2303 usb to UART IC from the PC side, the M3 uses MAX3243

I found there is a problem where the received data is wrong when I set:

#define UART1_BAUD             10400

However when I set “#define UART1_BAUD   1200”, the data is correct!

Test2:

Later on, I was using FTDI FT232B usb to UART IC from the PC side, the M3 uses MAX3243.

Both 10400 and 1200 work perfect!

Also, my colleague used LM3S9B90 in other project that uses UART0 to receive data from PC side. He found that some of the data is wrong (wrong rate is around 1%). He used an original COM port from the PC MatherBoard. He is using 19200 8n1, no s/w and h/w handshaking.

May I ask is there any compatibility issues on UART existed in 9B90?  

Since then, our projects are now getting stuck in the UART issue. Would you please provide any recommendation for us?

BR,

Barry Mok