16550 UART to Avalon

Hi Cris

First of all I tested my design with an integrated sopc uart to get confidence

with the following code:

void init_uart(int BAUD)
{
    int divi;
    divi = (50000000 / BAUD) + 0.5;
    IOWR_16DIRECT(UART_BASE, 0x14, divi);
}    // -- end of "init_uart()"
/* static void write_uart(char x)
 *
 * Send a character to the the PC
 */
void write_uart(char x)
{
    unsigned long status = 0;
    while((status & 0x00000040) != 0x00000040)
    {
        status = IORD_ALTERA_AVALON_UART_STATUS(UART_BASE);
    }
    IOWR_ALTERA_AVALON_UART_TXDATA(UART_BASE, x);
}    // -- end of "write_uart()"
/* char read_uart(void)
 *
 * Receive a character from the PC
 */
char read_uart(void)
{
    char x;
    x = IORD_ALTERA_AVALON_UART_RXDATA(UART_BASE);
    return x;
}    // -- end of "read_uart()"
int main(void)
{
    //int     iTx;  // initialize the Transmitter
    int i=0;
    char x='a';
    //char y=0x92;
    char z=64;
    init_uart(9600);
    x=read_uart();
    while (i<5)
    {
        write_uart(z);
        x=read_uart();
        z=z+1;
    }
    return 0;
}

It worked sucessfully.

Now I wanted to test in the same way my 16550 UART to Avalon by writting/reading to/from the registries.

But I don't know how to start .

Please I would appreciate your advices